Another: the hydraulic system for the three diseases, it was summed up: "fever, with a father拉稀" (This is the summary of the northeast people). Hydraulic system for the lifts, excavators, pumping station, dynamic, crane, and so on large-scale industry, construction, factories, enterprises, as well as elevators, lifting platforms, Deng Axle industry and so on.
    Hydraulic components will be high-performance, high-quality, high reliability, the system sets the direction of development; to the low power, low noise, vibration, without leakage, as well as pollution control, water-based media applications to adapt to environmental requirements, such as the direction of development; the development of highly integrated high power density, intelligence, mechatronics and micro-light mini-hydraulic components; active use of new techniques, new materials and electronics, sensing and other high-tech.
---- Hydraulic coupling to high-speed high-power and integrated development of hydraulic transmission equ- ipment, development of water hydraulic coupling medium speed and the field of automotive applications to develop hydraulic reducer, improve product reliability and working hours MTBF; hydraulic torque converter to the development of high-power products, parts and components to improve the manufacturing process tech -nology to improve reliability, promote computer-aided technology, the development of hydraulic torque con- verter and power shift transmission technology supporting the use of ; Clutch fluid viscosity should increase the quality of products, the formation of bulk to the high-power and high-speed direction.
   Comparison between cold rotary forging and conventional forging
Abstract
Cold rotary forging is an innovative incremental metal forming process, which is obviously different from the conventional forging process in many aspects, such as the metal flow, degree of inhomogeneous deformation of workpiece and force and power parameters. In the current work, a 3D elastic-plastic dynamic explicit FE model of cold rotary forging of a cylindrical workpiece is developed under the ABAQUS software environment and its validity has been verified by the experiment. Based on the reliable 3D FE model, the cold rotary forging and conventional forging process are simulated and their difference in the forming process has been thoroughly clarified. The research results may help to understand the cold rotary forging process better. Furthermore, they provide valuable guidelines for further  theoretical analysis and experimental studies on the cold rotary forging process.
1. Introduction
With the development of industrial technology, precision forging, or net-shape forging, has become increasingly popular due to savings in material, energy and finishing steps. However, many of the new components, because of their shape complexity and complicated tool design and high load requirements, are challenging the current precision forging technology beyond its current level of technology. To meet the requirement, there is a renewed interest in incremental forming, especially rotary-type incremental forming processes, such as swaging, cross-wedge rolling, ring rolling, spinning and rotary forging.  Compared with the conventional forging technology, cold rotary forging offers the following advantages [1]: lower level of noise and vibration, uniform quality, smooth surface, close tolerance and considerable savings in energy and materials cost. Additionally, because of the eccentric load in cold rotary forging, the stress state of cold rotary forging press is very complicated and the life of the bear is relatively low. At present, many studies have been done on the cold rotary forging process due to its significant advantages. In brief, these studies mainly focused on measuring the pressure distribution at the contact area [2], calculating and verifying the power parameters [3-6], and analyzing the metal flow [7-10] by using analytical and experimental methods. Meanwhile, the cold rotary forging process was analyzed by the rigidplastic FE method [11-14]. All of these research results provided useful guidelines for further theoretical analysis and experimental studies on the cold rotary forging process. However, the deformation characteristics and mechanism of cold rotary forging at present have not been fully understood. Especially, the difference between cold rotary forging and conventional forging needs to be thoroughly clarified and studied further in order to better understand the cold rotary forging process. Because cold rotary forging is a very complex metal forming technology with multi-factors coupling interactive effects, it is difficult to obtainsatisfactory results by analytical and experimental methods because of the limit of these methods. The finite element method has been proved a good method, which can obtain more detailed information in analyzing the metal forming processes. In cold rotary forging, the elastic deformation has a significant effect on the forming process and thus it is difficult to realize the acute simulation in the rigid-plastic FE analysis. Therefore, it is urgent to investigate the difference between cold rotary forging and conventional forging by the elastic-plastic FE method. 液压系统的英文文献及中文翻译(4):http://www.751com.cn/fanyi/lunwen_22554.html