Gear ratio and shift schedule optimization of wheel loader transmission for performance and energy efficiency

Sun

Proceedings of the Institution of Mechanical Engineers, Part D:

2021

The objective of this study was to evaluate the performance of 24 basic hydrodynamic mechanical power-split (HMPS) transmission designs effectively based on their torque multiplication capacities (TMCs) and efficiencies. Firstly, four schemes were preliminarily selected. Secondly, the matching between the four schemes and a reference wheel loader was considered, and an expression for the TMC was developed based on the traditional transmission and a second reference transmission. Thirdly, two performance metrics in terms of the TMC and efficiency – the average torque multiplication capacity (ATMC) and average efficiency – were defined to eliminate the couplings of four transmission parameters with the vehicle speed and speed ratio. Finally, the performances of the two best schemes and traditional hydrodynamic mechanical (HM) transmission were carefully compared. The results show that a transmission with power recirculation cannot present energy savings potential regardless of the ATMC, whereas a transmission with a power split can achieve an ATMC of 0.255, an average efficiency increment of 0.0143 in the short loading cycle, and a miniscule efficiency increment in the long loading cycle compared with the HM transmission.

Section: Introductionmentioning

confidence: 89%

Performance analysis of hydrodynamic mechanical power-split transmissions

Sun

Proceedings of the Institution of Mechanical Engineers, Part D:

2021

“…Aside from optimizing the performance of the torque converter, which is similar to an AT of an automobile, another effective change is to replace the transmission system with a clutch and gearbox. Oh et al [19] presented gear ratio and shift schedule optimization strategies to improve the energy efficiency in a dynamic simulation of a WL equipped with a DCT and an AMT. They showed through a simulation that the AMT based WL was more energy efficient than a T/C based WL, with an 11.9% energy consumption savings.…”

Section: Transmission Efficiencymentioning

confidence: 99%

An Overview of and Prospects for Research on Energy Savings in Wheel Loaders

Fei

Han

Wong

2023

Wheel loaders consume a large amount of energy, and research on energy savings in wheel loaders has been carried out for decades. This paper introduces several types of wheel loaders and compares their structures. The research progress of the energy savings of three different forms of wheel loaders is reviewed, including a diesel engine wheel loader, a hybrid wheel loader, and an electric wheel loader. In particular, the energy-saving control methods of an electric wheel loader in the working cycle are analyzed, as construction machinery electrification is an emerging trend. Based on the analysis of the driving features and the working process of a wheel loader, energy-saving control methods are introduced including the resistance reduction method, optimized control strategies, intelligent control, and unmanned WL research. Comparing various energy-saving research methods and the advantages of electric wheel loaders, the pure electric wheel loaders are advised to be researched at present and in the future. Controlling the torque distribution of the front and rear motors of electric wheel loaders and assistant drive control are proposed to be significant research prospects for energy savings in wheel loaders usage.

“…Although the four-parameter shift law takes into account the power consumed by the working pump and the power flow fluctuation caused by the work of the oil pump, the power consumed by the oil pump is equated to the reduction of the engine throttle opening, which is not in line with the actual working condition of the loader [14]. At the same time, because the engine and torque converter in the hydraulic transmission system of the loader is a highly nonlinear transmission system, it is difficult to solve such complex problems in the traditional linear control system, although some scholars have done some research in the intelligent control of the loader [15][16][17], but most of them use neural networks for shift control, and there is the problem of a low shift recognition rate [18,19]. Therefore, this paper takes a 7-ton wheel loader of a certain type as the research object, analyzes the operation mode of the loader, studies the multi-mode variable parameter shift law in depth, puts forward the RBF neural network intelligent shift control method for the application of the loader, and carries out the simulation and shift oil pressure test.…”

Section: Introductionmentioning

confidence: 99%

Research on Multi-Mode Variable Parameter Intelligent Shift Control Method of Loader Based on RBF Network

Wu,

Jin,

Wang

2024

Actuators

The loader is one of the most widely used pieces of engineering machinery in the world for soil transportation, loading and unloading materials, and low-intensity shovel digging operations in harsh and complex operating conditions; it requires very frequent shifting and has other challenging characteristics. In order to realize automatic frequent shifting, we need to better design the shifting rules in the shifting process, improve the shifting quality and working efficiency, and solve the key engineering problems of energy saving and high efficiency in the shifting process of loaders. In this paper, a 7-ton wheel loader is taken as the research object, the loader shoveling process of the four operating modes is analyzed, and a multi-mode variable parameter shift law is designed. Aiming at the complicated and nonlinear characteristics of the power transmission system of the loader, an intelligent shift control method based on an RBF neural network is proposed. Finally, the simulation test and the clutch shift oil pressure test are carried out. From the test results, the clutch test oil pressure curve obviously shows a four-stage upward trend during shifting, and the buffering effect is obvious. The designed multi-mode variable-parameter intelligent shift law of the loader is reasonable and feasible, and the shift recognition rate reaches 97.92%, which provides theoretical support for the realization of intelligent automatic speed change control of the loader, and it certainly has engineering value.