scholarly journals Power Transmission Efficiency of Planetary Gear Drives for Automatic Transmission of Automobiles.

1995 ◽  
Vol 61 (584) ◽  
pp. 1662-1668 ◽  
Author(s):  
Yong Chen ◽  
Akira Ishibashi ◽  
Yasuo Sumi
Keyword(s):  
Power Transmission ◽  
Automatic Transmission ◽  
Planetary Gear ◽  
Transmission Efficiency ◽  
Gear Drives

scholarly journals Advanced Power Transmission System

2012 ◽  
Vol 23 (2) ◽  
pp. 191-207
Author(s):  
Rafea M. Abd El-Maksoud Rafea M. Abd El-Maksoud
Keyword(s):  
High Performance ◽  
Power Transmission ◽  
Automatic Transmission ◽  
Planetary Gear ◽  
Torque Converter ◽  
Transmission System ◽  
Present System ◽  
Power Splitting ◽  
Operating Modes ◽  
Power Transmission System

Different researches are adopted to modify and enhance automatic transmission by every means. Whereas, torque converter that represents the most important component in such transmission suffers from some problems that are not completely solved. In this paper, power transmission system is herein introduced as a unique power transmission system that is not affected by torque converter problems. This power transmission operates with power splitting concept and is composed of conventional torque converter connected to planetary sets. Three clutches are used to shift the operating modes and unique positive displacement hydraulic couplings are utilized to regulate performance in power paths. Also, a modified model used to predict torque converter performance is utilized with planetary gear kinetics to assess the transmission performance. Moreover, the present system operates with high performance. Unlike the automatic transmission that operates in line, the present system operates with infinity number of operational bands for each engine speed.

scholarly journals Loader power-split transmission system based on a planetary gear set

2018 ◽  
Vol 10 (1) ◽  
pp. 168781401774773 ◽  
Author(s):  
Chang Lyu ◽  
Zhao Yanqing ◽  
Lyu Meng
Keyword(s):  
Output Power ◽  
Fuel Economy ◽  
Power Transmission ◽  
Planetary Gear ◽  
Torque Converter ◽  
Transmission Efficiency ◽  
Transmission System ◽  
Mechanical Transmission ◽  
Power Split ◽  
Hydraulic Torque Converter

In hydraulic mechanical transmission loaders, a hydraulic torque converter can prevent an engine from stalling due to overloading of the loader during the spading process; however, the hydraulic torque converter also reduces the loader’s fuel economy because of its low transmission efficiency. To address this issue, the study designs an output-power-split transmission system that is applied to a hybrid loader. The designed transmission system removes the hydraulic torque converter in the power transmission system of a traditional loader and adopts a planetary gear set with a compact structure as the dynamic coupling element, thus allowing the output power of the loader to be split transmitted. During shoveling, the loader power-split transmission system based on a planetary gear set can prevent the motor from plugging and over-burning under conditions that ensure that the traction does not decrease. In addition, the transmission efficiency and loader fuel economy are higher in the proposed transmission system than in the power transmission system of a traditional loader. The test results show that the transmission efficiency of the designed system was 13.2% higher than that of the traditional hydraulic mechanical transmission loader.

The effect of planetary gear/star gear on the transmission efficiency of closed differential double helical gear train

2020 ◽  
Vol 234 (21) ◽  
pp. 4215-4223
Author(s):  
Cheng Wang
Keyword(s):  
Power Flow ◽  
Power Transmission ◽  
Flow Direction ◽  
Load Capacity ◽  
Research Work ◽  
Planetary Gear ◽  
Transmission Efficiency ◽  
Helical Gear ◽  
Gear Train ◽  
Graph Representation

The research of transmission efficiency is of great significance for reducing energy consumption and improving the performance of the device. Researchers have done a lot of work on the calculation of transmission efficiency. However, in the present research work, the quantity of planetary gear/star gear is usually not considered and only a planetary gear/star gear is adopted in the gear transmission efficiency. In practice, in order to increase the stiffness and load capacity of gear train, a plurality of planetary gear/star gears is adopted. The closed differential double helical gear train has been widely used in many fields, such as the main reducer of aircraft engine, lifting mechanism, and the power transmission system of marine ships. Therefore, in this paper, the closed differential double helical gear train is taken as the research object and the effect of planetary gear/star gear on the transmission efficiency is analyzed. Firstly, according to the structure of closed differential double helical gear train, related kinematic analysis is given. Secondly, a graph representation is used to characterize the closed differential double helical gear train. According to the theory of virtual power, the power flow direction of closed differential double helical gear train is determined and the value of split power is obtained. According to the input and output values described in graph representation of closed differential double helical gear train, the formula of transmission efficiency is derived and the effects of planetary gear/star gear on transmission efficiency are analyzed. Finally, an illustrative example shows that compared with the theoretical value, the difference considering the effect of planetary gear/star gear on the transmission efficiency of closed differential double helical gear train is two percentage points.

A study on the development and application of program for planetary gear design considering planetary gear noise and efficiency

2021 ◽  
Vol 263 (5) ◽  
pp. 1516-1526
Author(s):  
Hyun Ku Lee ◽  
Moo Suk Kim ◽  
Sa Man Hong ◽  
Dong Kyu Yoo ◽  
Ahmet Kahraman ◽  
...  
Keyword(s):  
Input Parameter ◽  
Automatic Transmission ◽  
Planetary Gear ◽  
Transmission Efficiency ◽  
Design Stage ◽  
Concept Design ◽  
Mechanical Loss ◽  
Gear Noise ◽  
Gear Design ◽  
Planetary Gear Sets

In general, gear mechanical loss is associated with the friction of the lubricating contact surface of the gear and bearing that transmit the power, and a no-load spin loss which is load independent occurs due to gear rotation and the interaction of the bearing component with the lubricating element. In order to minimize planetary gear loss, it is desirable to design by checking the efficiency at the concept design stage. However, a design technique that considers the noise and efficiency of a planetary gear set simultaneously has not been achieved so far. In this paper, a program called 'pRMC with EHL' to check together the efficiency and noise that affected by gear specifications has been developed. By using developed program, planetary gear sets specifications have been designed. And through the experimental evaluation, automatic transmission efficiency could be reduced by 0.3% in combination fuel consumption mode and the planetary gear vibration could be also reduced by 10 dB than former design. Through this designing verification and input parameter correlation, a new planetary gear set designing process has been come up with successfully at the concept design stage.

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.

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