Analysis on Hydrodynamic Pressure-loading Effect of Port Plate Pairs with Bionic Non-smooth Surface for Sea Water Low-speed and High-torque Hydraulic Motor

Author(s):  
Gao Dianrong ◽  
Liu Jingcheng ◽  
Zhang Zongyi
Author(s):  
S K Mandal ◽  
K Dasgupta ◽  
S Pan ◽  
A Chattopadhyay

In this article the steady-state models of an open-circuit and a closed-circuit hydrostatic transmission (HST) drive have been developed to study their performances. A low-speed high-torque multi-stroke cam plate type radial piston motor is considered for both HST drives. Bondgraph simulation technique has been used to model the drives. The multi-bondgraph representation of the HST drives is presented; it takes into account the compression and expansion phases, which occur sequentially in the hydraulic motor. A reduced bondgraph model of the drives has been proposed, where various losses are lumped into suitable resistive elements. The relationships of the loss coefficients with other state variables, obtained from the reduced model, are identified through experimental investigation. The loss coefficients are found to have a non-linear relationship with the load torque and the supply flowrate. Using the characteristics of these loss coefficients, the steady-state performances of the hydrostatic drives are studied in Part 2 of this article (pg. 2675 of this issue).


Author(s):  
Zhiqiang Wang ◽  
Shaofeng Wu ◽  
Dianrong Gao ◽  
Shuncai Wang

AbstractThe current research of seawater hydraulic motor mainly focused on piston motor and vane motor, but seldom regarded low speed high torque seawater hydraulic motor. Low speed high torque seawater hydraulic motor as a kind of energy conversion device and actuator plays an important role in seawater hydraulic transmission system. However, the physical and chemical properties of seawater, such as low viscosity, high causticity and poor lubrication, result in numerous problems. In this paper, the flow distribution characteristics of port plate pairs for the seawater hydraulic motor are investigated, and the leakage flow and power loss models of port plate pairs are established. Numerical simulations are carried out to examine the effects of water film, inlet pressure and rotating speed on the pressure distribution and leakage flow. And the friction and wear tests of port plate pairs are also carried out. Moreover, the test system of the seawater hydraulic motor is constructed and the performance of prototype with no-load or loading is conducted. The results indicate that the clearance of port plate pairs and inlet pressure have a significant effect on distribution characteristics, but the effect of rotating speed is not very obvious. The experimental results show that the minimum error rate can be maintained within 0.3% by the proposed flow model and the counter materials of 316L against carbon-fiber-reinforced polyetheretherketone (CFRPEEK) are suitable for the port plate pairs of seawater hydraulic motor. Finally, based on the seawater hydraulic experiment platform, the volumetric efficiency of no-load and loading are obtained that the maximum can achieve 94.71% and 90.14%, respectively. This research work may improve the flow distribution performance, lubrication and the friction and wear properties, enhance energy converting efficiency of port plate pair and provide theoretical and technical support for the design of high-performance water hydraulic components.


Author(s):  
Bingjing Qiu ◽  
Jiyun Zhao ◽  
Liang Zhao

High water-based hydraulic motors (HWBHMs) with advantages including higher specific power and shorter acceleration and braking time can be used to directly drive loads. In particular, low speed and high torque high water-based hydraulic motors work well in limited space and for special applications (open flame areas). However, traditional structure and flow distribution mechanisms cause serious leakage and lower work efficiency for low speed and high torque high water-based hydraulic motors. Thus, a new structure and flow distribution mechanism with self-balanced distribution valve groups for a high water-based hydraulic motor need to be developed to work in high pressure, low speed, and high torque conditions. In this paper, a high water-based hydraulic motor was theoretically analyzed and the working principle behind a high water-based hydraulic motor was briefly introduced. Numerical simulations were performed to examine the effects of the distribution valve parameters on the distribution performance. An orthogonal test method was used to determine the optimized structure parameters. A simulation model of a high water-based hydraulic motor was established using the AMESim simulation method to validate the feasibility of the optimized structure parameters. This research has laid a foundation for the further development of a high water-based hydraulic motor with low speed and high torque.


Author(s):  
K Dasgupta ◽  
A Mukherjee ◽  
R Maiti

In this paper the steady state performance of epitrochoid generated orbital ‘rotary piston machine’ (ROPIMA) type ‘low-speed high-torque’ (LSHT) hydrostatic unit has been studied. The complex variation of the volume of a chamber of such a machine with shaft rotation, along with the various flow and torque losses, demand a structured approach to arrive at its mathematical model. In conventional approaches the system morphology becomes obscured as the mathematical model is approached. Bondgraph provides a structured approach to model engineering systems in a simplified manner. A reduced Bondgraph model of the LSHT Orbital motor is made where the various losses are lumped in suitable resistive elements. The variations of the loss coefficients are identified. The predicted performance of the motor has been experimentally verified.


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