scholarly journals Efficiency Evaluation of Electric Bicycle Power Transmission Systems

2021 ◽  
Vol 13 (19) ◽  
pp. 10988
Author(s):  
Sheng-Peng Zhang ◽  
Tae-Oh Tak
Keyword(s):  
Power Transmission ◽  
Dominant Role ◽  
Transmission Efficiency ◽  
Design Stage ◽  
Power Train ◽  
Inertia Effects ◽  
Motor Torque ◽  
Road Load ◽  
Electric Bicycle ◽  
Electric Bicycles

In this study, a method for estimating the efficiency of electric bicycle power train systems consisting of typical components, such as an electric motor, gears, sprockets, and chains is presented. In order to calculate the efficiency of a power train system, the relationship between the drive motor torque and the road-load that is exerted on the rear wheel was derived, considering kinematic inertia effects and friction losses between power transmission elements. Among the factors that influence efficiency, it was found that friction losses play a dominant role, while the effects of inertia are insignificant. The factors that influence the efficiency of electric bicycles due to friction losses, such as the transmission efficiency of the chain system and the bearing in the sprocket and wheel, were quantified. To validate the proposed efficiency calculation procedure, an experimental electric bicycle was used, in which the driving torque and road-load could be quantitatively assessed, and the actual efficiency was measured on a chassis dynamometer. It is shown that for a given motor torque, a measured and estimated dynamometer torque obtained by the proposed method exhibits a good correlation, and the transmission efficiency of each component was quantified. This method provides a practical and accurate means to calculate the drive train efficiency of electric bicycles at the design stage to improve the efficiency of electric bicycles.

Integrated Product and Process Design for a Flapping Wing Drive Mechanism

2009 ◽  
Vol 131 (6) ◽  
Author(s):  
Wojciech Bejgerowski ◽  
Arvind Ananthanarayanan ◽  
Dominik Mueller ◽  
Satyandra K. Gupta
Keyword(s):  
Power Transmission ◽  
Transmission Efficiency ◽  
Flapping Wing ◽  
Point Of View ◽  
Design Stage ◽  
Molding Process ◽  
Drive Mechanism ◽  
Battery Capacity ◽  
Product And Process ◽  
The Impact

Successful realization of a flapping wing micro-air vehicle (MAV) requires development of a light weight drive mechanism that can convert the continuous rotary motion of the motor into oscillatory flapping motion of the wings. The drive mechanism should have low weight to maximize the payload and battery capacity. It should also have high power transmission efficiency to maximize the operational range and to minimize weight of the motor. In order to make flapping wing MAVs attractive in search, rescue, and recovery efforts, they should be disposable from the cost point of view. Injection molded compliant drive mechanisms are an attractive design option because of manufacturing scalability and reduction in the number of parts. However, realizing compliant drive mechanism using injection molding requires use of multipiece multigate molds. Molding process constraints need to be considered during the design stage to successfully realize the drive mechanism. This paper describes an approach for determining the drive mechanism shape and size that meets both the design and molding requirements. The novel aspects of this work include (1) minimizing the number of mold pieces and (2) the use of sacrificial shape elements to reduce the impact of the weld-lines on the structural performance. The design generated by the approach described in this paper was utilized to realize an operational flapping wing MAV.

Improving the efficiency of oilfield electric power distribution

2019 ◽  
pp. 79-87
Author(s):  
Yu. F. Yu. F. Romaniuk ◽  
О. V. Solomchak ◽  
М. V. Hlozhyk
Keyword(s):  
Power Distribution ◽  
Reactive Power ◽  
Power Transmission ◽  
Transmission Efficiency ◽  
Active Power ◽  
Oil Field ◽  
Total Power ◽  
Simultaneous Increase ◽  
Active Load ◽  
Step Down

The issues of increasing the efficiency of electricity transmission to consumers with different nature of their load are considered. The dependence of the efficiency of the electric network of the oil field, consisting of a power line and a step-down transformer, on the total load power at various ratios between the active and reactive components of the power is analyzed, and the conditions under which the maximum transmission efficiency can be ensured are determined. It is shown by examples that the power transmission efficiency depends not only on the active load, but also largely on its reactive load. In the presence of a constant reactive load and an increase in active load, the total power increases and the power transmission efficiency decreases. In the low-load mode, the schedule for changing the power transmission efficiency approaches a parabolic form, since the influence of the active load on the amount of active power loss decreases, and their value will mainly depend on reactive load, which remains unchanged. The efficiency reaches its maximum value provided that the active and reactive components of the power are equal. In the case of a different ratio between them, the efficiency decreases. With a simultaneous increase in active and reactive loads and a constant value of the power factor, the power transmission efficiency is significantly reduced due to an increase in losses. With a constant active load and an increase in reactive load, efficiency of power transmission decreases, since with an increase in reactive load, losses of active power increase, while the active power remains unchanged. The second condition, under which the line efficiency will be maximum, is full compensation of reactive power.  Therefore, in order to increase the efficiency of power transmission, it is necessary to compensate for the reactive load, which can reduce the loss of electricity and the cost of its payment and improve the quality of electricity. Other methods are also proposed to increase the efficiency of power transmission by regulating the voltage level in the power center, reducing the equivalent resistance of the line wires, optimizing the loading of the transformers of the step-down substations and ensuring the economic modes of their operation.

Compensating Resonant Frequency via Adjusting Adjustable Coil Automatically

2019 ◽  
Vol 12 (5) ◽  
pp. 432-438
Author(s):  
Jin Xu ◽  
Yuting Zhao
Keyword(s):  
Resonant Frequency ◽  
Power Transmission ◽  
Reference Value ◽  
Transmission Efficiency ◽  
Theoretical Research ◽  
Future Research ◽  
Wireless Power ◽  
Wireless Power Transmission ◽  
Resonant Coupling ◽  
Transmission Distance

Background: Detuning is the main problem that affects the efficiency and transmission distance of the resonant coupling Wireless Power Transmission (WPT). The distance of load and the offset of the load position could cause serious detuning. Methods: This paper presents an adjustable coil in which inductance can be adjusted. Then a model of WPT was established that could compensate resonant frequency automatically using the adjustable coil. Next, the relationship between the primary resonant frequency and the transmission efficiency is analyzed from the circuit. The analysis proved that the design of the adjustable coil could improve the transmission efficiency of the WPT system. Finally, a prototype of WPT system was built. Results: The experimental results showed that WPT system with adjustable coil can improve the transmission efficiency which proves the theoretical research. At the same time, it has essential reference value for the future research of WPT. Conclusion: In this paper, aiming at the system detuning caused by some other factors, such as the position shift of the load during the wireless power transmission, an adjustable coil is proposed.

scholarly journals Power Train Designing for Formula styled Racing Car

2021 ◽  
Vol 9 (10) ◽  
pp. 1883-1901
Author(s):  
Malav Sevak
Keyword(s):  
Power Transmission ◽  
Suspension System ◽  
Previous Model ◽  
Brake System ◽  
Maximum Acceleration ◽  
Power Train ◽  
The Road ◽  
Work Done

Abstract: A wheel assembly is an integral part of a vehicle’s design that connects the wheel to the suspension system and transfers pressure from the road to the suspension system. It also holds the brake system and facilitates steering. Power transmission is also addressed in the powertrain department. We describe the process and simulation that result in the hub, upright, and differential mounting of a formula student car and the size of the sprocket for maximum acceleration in this report. As a result of the work done on this project, the resulting car has improved acceleration, is easy and reliable to assemble, and has fewer breakdowns than the previous model. The report includes all the calculations that support the simulations and a validating statement about the bearing selection.

scholarly journals Design of a Loop Resonator with Improved Power Transmission Efficiency Using a Ferrite Plate

2013 ◽  
Vol 05 (05) ◽  
pp. 196-200 ◽  
Author(s):  
Gangil Byun ◽  
Sunghwan Ji ◽  
Byungjun Jang ◽  
Chulhun Seo ◽  
Hosung Choo
Keyword(s):  
Power Transmission ◽  
Transmission Efficiency ◽  
Ferrite Plate
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