Efficiency Analysis on Hydro-Mechanical Transmission

2014 ◽  
Vol 1037 ◽  
pp. 216-220
Author(s):  
Zhen Zhu ◽  
Xiang Gao ◽  
Dao Yuan Pan ◽  
Yu Zhu

In order to study the efficiency on hydro-mechanical transmission (HMT),this paper analyses the stepless speed regulation characteristic,torque characteristic and hydraulic power distributing characteristic of HMT.According to the calculating method of efficiency of the closed pump-motor system and planetary gear,the approximate efficiency formulas of HMT were established.The result shows that:the efficiency of HMT is much higher than that of hydrostatic transmission (HST),the peak efficiency of HMT can reach about 90% and the average efficiency of HMT can exceed more than 80%.

2014 ◽  
Vol 1037 ◽  
pp. 107-110 ◽  
Author(s):  
Xi Yin Lou

Crawler combine harvester walking system is various transmission technology are organic and reasonable matching, foster strengths and circumvent weaknesses, complementary drive system so as to achieve the best overall. Stepless speed walking is particularly suitable for complex condition changes, the demand of drive system for a more comprehensive, more comprehensive, objective stepless speed walking in transmission system innovation or seek better performance, and as a mechanical transmission device of the planetary gear has the advantages of small volume transfer large torque, high efficiency. The combination of both realizes stepless transmission, and has the advantages of low speed and high torque. Hydraulic drive system is mainly to achieve stepless speed regulation, commutation, planetary gear drive mainly reduce speed, increase the torque to. Composite transmission mode that can greatly improve the transmission ability, expand the scope of speed adjustment. In fact, combine the stepless variable speed running and control technology can greatly improve the performance of the product, especially the effect on production efficiency, durability, controllability, environment adaptability, green characteristics were significantly.


2021 ◽  
Author(s):  
Johnathan (Hans) Barkei ◽  
Perry Y. Li

Abstract A hydro-mechanical transmission (HMT) transmits power both mechanically and hydraulically allowing continuously variable transmission ratios and more efficient transmission than hydrostatic transmission. A conventional HMT tends to be costly and bulky since it has a hydrostatic transmission in parallel with a mechanical transmission. An alternative is a compact inline configuration that utilizes a two-shafted pump that is mechanically and hydraulically connected to a motor. This avoids the need for a planetary gear set while providing the HMT functionality. When the pump/motor displacement is zero, all of the power is transmitted mechanically and the transmission ratio is unity, a condition referred to as lock-up that is expected to be very efficient. Previous research however has shown significant losses at this operating condition in experiments. This is thought to be caused primarily by compressibility losses due to the repeated unnecessary opening and closing of the distributor valves. This paper first models the Hondamatic in simulations to confirm that compressibility losses contribute to the low efficiency at lock-up. Second, the paper proposes a solution to reduce these compressibility losses by means of a second cam mode that closes the distributor valves to prevent flow between the piston and the high and low pressure volumes. The performance of the existing inline HMT and the proposed solution at lock-up are modeled in simulations and compared. The results indicate a 10% increase in efficiency at lock-up.


Author(s):  
Jin Yu ◽  
Pengfei Shen ◽  
Zhao Wang ◽  
Yurun Song ◽  
Xiaohan Dong

Heavy duty vehicles, especially special vehicles, including wheel loaders and sprinklers, generally work with drastic changes in load. With the usage of a conventional hydraulic mechanical transmission, they face with these problems such as low efficiency, high fuel consumption and so forth. Some scholars focus on the research to solve these issues. However, few of them take into optimal strategies the fluctuation of speed ratio change, which can also cause a lot of problems. In this study, a novel speed regulation is proposed which cannot only solve problems above but also overcome impact caused by speed ratio change. Initially, based on the former research of the Compound Coupled Hydro-mechanical Transmission (CCHMT), the basic characteristics of CCHMT are analyzed. Besides, to solve these problems, dynamic programming algorithm is utilized to formulate basic speed regulation strategy under specific operating condition. In order to reduce the problem caused by speed ratio change, a new optimization is applied. The results indicate that the proposed DP optimal speed regulation strategy has better performance on reducing fuel consumption by up to 1.16% and 6.66% in driving cycle JN1015 and in ECE R15 working condition individually, as well as smoothing the fluctuation of speed ratio by up to 12.65% and 19.01% in those two driving cycles respectively. The processes determining the speed regulation strategy can provide a new method to formulate the control strategies of CCHMT under different operating conditions particularlly under real-world conditions.


2018 ◽  
Vol 10 (8) ◽  
pp. 2697 ◽  
Author(s):  
Yun-Gi Hwang ◽  
Soohyun Park ◽  
Daecheol Kim

Results of the CDI and QODA evaluation developed by OECD showed that Korea’s aid presented low efficiency compared to other aid countries. However, these methods represent a qualitative assessment of the effectiveness of each country’s aid and are not applicable to the evaluation of actual aid projects and the identification of causes of the inefficiency. Therefore, it is needed to grasp the reality of Korea’s aid and to identify the cause of aid inefficiency to set up a better ODA policy. The purpose of this study is to improve the effectiveness of Korea’s Official Development Assistance (ODA) provided to developing countries. To do this, we analyzed the efficiency of ODA provided to 33 recipient countries by Korea through data envelopment analysis method. The effects of three factors, illiteracy, integrity, and GDP, on efficiency were also investigated by utilizing a Tobit regression analysis. As a result of the DEA efficiency analysis, it was found that the average efficiency was about 65.74%. By region, the average efficiency scores of Asia, Africa, Central and South America, and Middle East and Eastern Europe were about 47.8%, 78.9%, 70.4%, and 62.7%, respectively. This indicates that Asian countries are inefficient compared to countries from other regions. It was also found that GDP, integrity, and illiteracy have positive effects on efficiency. The methodology proposed in this study can be used for other studies to create an aid policy that produces efficient results.


2010 ◽  
Vol 56 (No. 2) ◽  
pp. 89-96 ◽  
Author(s):  
M.M. Artukoglu ◽  
A. Olgun ◽  
H. Adanacioglu

This paper investigates technical and economically efficiency of 62 organic and 62 conventional olive producing farms in Turkey. According to the study results; by using the CRS model which is input and output-oriented, the average technical efficiency of organic olive farms is 67.68%, the average technical efficiency of conventional olive farms is 47.93%. The technical efficiency of the output-oriented VRS model is 74.78%, and the technical efficiency of the input-oriented VRS model is 93.46%. Also, considering the same model, the average efficiency of the conventional olive farms in the input and output are 59.58% and 94.97%, respectively. Therefore, according to the Data Envelopment Analysis, the technical efficiency in conventional olive farms is less than in the organic ones. When the farms have been evaluated one by one in the light of the total potential improvement values, inputs and outputs, improvement is needed in all values.


2011 ◽  
Vol 697-698 ◽  
pp. 445-449
Author(s):  
Lian Jie Ma ◽  
M. Sun ◽  
Ya Dong Gong

Through design of balancing movement controller of large size workpiece for applying to LDMC-100 type ion nitriding furnace, the structure and principle of mechanism were introduced, the balance of mechanical transmission and influencing to nitriding layer of workpiece surface were analysed. In this mechanism, the planetary gear system was adopted, the single axis was adopted in this supporting mechanism, and the electric and insulating on workpieces were used. The balancing influencing of movement and techniques parameters for nitriding layer were discussed. The results indicate, the nitriding period is related with input speed and number of driven gear teeth. The re-nitriding rate and blank nitriding rate are related with gear modulus, workpiece outside diameter, number of drive and driven gear teeth. When the mechanism structure parameter is fixed, the effect of nitriding was completed by changing speed of input axis.


2012 ◽  
Vol 472-475 ◽  
pp. 753-756
Author(s):  
Fu Yi Cao ◽  
Zhi Li Zhou ◽  
Hong Jie Zhao

The hydro-mechanical differential turning mechanism is the new type of double power flow turning mechanism of tracked vehicle. The hydraulic stepless speed regulation and the high efficiency of mechanical transmission are integrated into the turning mechanism. The stepless turning of tracked vehicle can be achieved. Basing on hydro-mechanical differential turning theory, the scheme design of steering wheel control system of tracked vehicle of hydro-mechanical differential turning is finished. By establishing model of steering wheel control system, its working stability and following characteristic is simulated and analyzed in this paper. The demand of hydro-mechanical differential turning of tracked vehicle can be realized by the steering wheel control system designed through the simulation results.


2017 ◽  
Vol 2017 ◽  
pp. 1-16 ◽  
Author(s):  
Ting Yan ◽  
Lin Yang ◽  
Bin Yan ◽  
Wei Zhou ◽  
Liang Chen ◽  
...  

Considering the inherent disadvantages that severely affect driving comfortability during the shift process in HEVs, a dynamic shift coordinated control based on motor active speed synchronization is proposed to improve shift quality by reduction of shift vibration. The whole control scheme is comprised of three phases, preparatory phase, speed regulation phase, and synchronization phase, which are implemented consecutively in order. The key to inhibiting impact and jerk depends on the speed regulation phase, where motor active speed synchronization is utilized to reach the minimum speed difference between the two ends of synchronizer. A new hybrid system with superior performances is applied to present the validity of the adopted control algorithm during upshift or downshift, which can represent planetary gear system and conventional AMT shift procedure, respectively. Bench test, simulation, and road test results show that, compared with other methods, the proposed dynamic coordinated control can achieve shifting control in real time to effectively improve gear-shift comfort and shorten power interruption transients, with robustness in both conventional AMT and planetary gear train.


2021 ◽  
Vol 32 (1) ◽  
pp. 111-116
Author(s):  
Uranbaigal Dejidbal ◽  
Lkhagvadorj Batsambuu

One of the main sources of development and livelihood in our country comes from  the production of the agricultural sector, only second after the mining industry. Agricultural sector not only supplies food and essential nutrients but it is a source of income and employment. The main labor force in this sector  consists of herders, and the  best way to ensure their livelihood is to increase the number of  livestock. However, there are different ways to calculate costs and revenues of pastoral livestock production. Nomadic herder households have different income sources and expenses depending on the type of livestock that they herd and it varies by region. The study focuses on households herding horses and aims to conduct    efficiency analysis on the household f income and expenses using  the  data gathered by the survey. The household income and expenses depend on what type of livestock they are herding. Households that are herding horses are surveyed through written surveys in this study. The economic efficiency methodology was used in the analysis. Furthermore, the study analysed statistics of the productivity of livestock. The study finds that a high number of horses are correlated with highly efficient income levels from the livestock. According to the survey results, in the Khangai region, the average efficiency level of all regions is 104.08%, and the steppe zone is 14.55%. Адууны аж ахуйн бүтээгдэхүүн үйлдвэрлэлийн эдийн засгийн үр ашгийн шинжилгээ Манай орны хөгжлийн гол тулгуур багануудын нэг нь  уул уурхайн дараа хөдөө аж ахуйн салбар түүн дотроо мал аж ахуйн  үйлдвэрлэл  ордог. Энэ салбарын хөдөлмөрийн гол нөөц малчид бөгөөд тэдний амьжиргааны баталгаат байдлыг хангах гол эх үүсвэр нь мал, малын тоо толгойн өсөлт байсаар ирсэн байна. Бэлчээрийн мал аж ахуйн үйлдвэрлэлийн зардал, орлогын талаар харьцангуй ялгаатай ойлголтууд байсаар байна. Малчин өрхийн хувьд малын төрлөөс шалтгаалан орлого, зардлын бүтэц ялгаатай бөгөөд адуун сүргийн хувьд орлого болон зардлын хэмжээг өрх бүрээр анкет-асуулгын аргаар бүртгэн авч үр ашгийн түвшнийг тооцоолон, дүгнэлт гаргах зорилго тавьсан болно. Малчин өрхийн адууны аж ахуйгаасаа олох орлого, зардлын зөрүү нь  адууны толгойн тооноос гадна бүс нутгийн байршлаас хамаардаг байна. Бэлчээрийн мал аж ахуйн салбаруудын дотроос оны эхний 1 толгойгоос үйлдвэрлэж буй бүтээгдэхүүний хэмжээгээр хамгийн их нь монгол үхэр, дараа нь тэмээ, адуу, хамгийн бага нь ямаа, хонь байна. [1] Адууны аж ахуйн хувьд бэлчээр, тэжээл, арчилгаа, маллагаа, хашаа саравч зэрэгт зарцуулах зардал бусад малд зарцуулах зардалтай харьцуулбал бага бөгөөд харин амьдаар болон маханд зориулж зах зээлд борлуулах, мах, сүүн ашиг шимийг ашиглах зэргээс олох орлогын хэмжээ бусад малтай харьцуулбал өндөр байгаа нь орлого, зардлын зөрүү их байх нөхцөлийг бүрдүүлдэг учраас адууны аж ахуйн үр ашиг нэлээд өндөр байх болно гэсэн таамаглал дэвшүүлэн судалгааг явууллаа. Бэлчээрийн мал аж ахуйн үйлдвэрлэлийн тэр тусмаа адууны аж ахуйгаас олох орлого болон зардлын бүртгэл харьцангуй бага, бүдэг байгаа учраас судалгааг өрх бүрд очиж гэрийн эзэд, эзэгтэйгээс асуулгын аргаар тодруулан бүртгэж авсан болно. Судалгаанд үр ашгийн түвшнийг тооцох арга зүйг  ашигласан бөгөөд судалгаанд хамрагдсан өрхүүдийг малын тоогоор бүлэглэн шинжилгээг гүйцэтгэсэн юм. Малчин өрхүүдийн адууны толгойн тооны ялгаатай байдал нь адууг адгуулан маллах, өсгөж үржүүлэхэд зарцуулах зардал, адууны ашиг шим, бүтээгдэхүүний борлуулалтаас олох орлогын бүтцэд нэлээд нөлөөтэй байгаа нь ажиглагдсан болно.  Судалгааны үр дүнгээс харахад Хангайн бүсийн  дунджаар үр ашгийн түвшин 104.08%, хээрийн бүс 14.55% байна.  Түлхүүр үг: Гүүний айраг,  Хангайн бүс, Хээрийн бүс, малчин өрх, орлого, зардал.  


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