A Novel Pressure-Controlled Hydro-Mechanical Transmission

2014 ◽  
Author(s):  
Feng Wang ◽  
Kim A. Stelson
Keyword(s):  
Fundamental Principle ◽  
Transmission Efficiency ◽  
Control Flow ◽  
Drive System ◽  
Output Shaft ◽  
Mechanical Transmission ◽  
Hydraulic Motor ◽  
Vane Pump ◽  
Variable Displacement ◽  
Pressure Controlled

A novel pressure-controlled hydro-mechanical transmission (PHMT) is studied in this paper. The PHMT consists of a pressure-controlled hydraulic transmission (PCT) and a variable displacement hydraulic motor. The PCT functions like a conventional hydrostatic transmission (HST) but has a different form. It uses a double-acting vane pump with a floating ring. By coupling the floating ring to an output shaft, the vane pump becomes a hydraulic transmission. The PCT combines the pumping and motoring functions in one unit, making it much simpler than a conventional HST. By controlling the pressure in the PCT, the output shaft torque and speed can be adjusted. By feeding the PCT control flow to a variable displacement motor coupled to the PCT output shaft, a PHMT is constituted. In this paper, the fundamental principle of the PHMT is studied. To demonstrate its advantage, the PHMT is applied to a fan drive system and the transmission efficiency is compared to a conventional HST. Preliminary experimental results show that the input power of the fan drive system with a PHMT is lower than that with an HST given the same output fan speed and torque.

Performance Study of Vane Pump Power Split Transmission for a Highway Vehicle

2015 ◽  
Author(s):  
Biswaranjan Mohanty ◽  
Feng Wang ◽  
Kim A. Stelson
Keyword(s):  
Pump Power ◽  
Continuous Variable ◽  
Control Flow ◽  
Output Shaft ◽  
Performance Study ◽  
Hydraulic Motor ◽  
Vane Pump ◽  
Engine Operation ◽  
Power Split ◽  
Variable Displacement

A novel Vane Pump Power Split Transmission (VPPST), applied to a class 1 pickup truck, is demonstrated in this paper. The VPPST, a power split hydraulic transmission consists of Vane Pump Power Split Unit (VPSU) and a variable displacement hydraulic motor. The VPSU is a double acting vane pump with a floating ring. The floating ring is coupled to the output shaft, which is connected to the drive shaft. The input shaft of the VPSU is coupled to the engine. The control flow of the VPSU is fed to a variable displacement motor mounted on the VPSU output shaft. The transmission ratio is adjusted by controlling the displacement of the variable motor. The resulting continuous variable transmission allows for optimum engine operation by decoupling the engine speed from the drive speed. The transmission also has an integral clutch that allows de-clutching the engine from the drive train by retracting the vanes of the VPSU. In this paper, a quasi-static simulation approach is used to study the performance of the transmission.

A Three-Dimensional CFD Methodology to Study Vane-Ring and Vane-Under-Vane Interactions of a Vane Pump Power Split Transmission

2016 ◽  
Author(s):  
Emma Frosina ◽  
Adolfo Senatore ◽  
Dario Buono ◽  
Kim A. Stelson ◽  
Feng Wang ◽  
...  
Keyword(s):  
Pump Power ◽  
Model Building ◽  
Three Dimensional ◽  
Output Shaft ◽  
University Of Minnesota ◽  
Hydraulic Motor ◽  
Vane Pump ◽  
Input Shaft ◽  
Power Split ◽  
The University

This paper presents a study of a novel vane pump power split transmission (VPPST). The transmission incorporates a new component, the Vane Power Split Unit (VPSU). The VPSU is a double-acting vane pump with a floating ring where the input shaft is connected to the engine and the floating ring is connected to the output shaft. The VPSU generates hydraulic oil flow at a rate proportional to the difference in angular velocities between the input and output shafts. This flow enters a hydraulic motor mounted to the output shaft. The vane pump power split transmission (VPPST) is a combination of the double-acting vane pump (VPSU) and the hydraulic motor directly connected to the pump. A CFD model of the VPSU has been created to better understand its performance. The model uses the three-dimensional CFD commercial code PumpLinx®, developed by Simerics® Inc. Thanks to collaboration with the code developers, the model is able to predict the complex fluid dynamics in the pockets in the rotor into which the vanes retract. These pockets are referred to as under-vane volumes. The rotor of the vane pump, in fact, has several internal channels that connect the pumping chambers between the vanes to the under-vane volumes. The combination of the vanes and the internal ducts and volumes of the under-vanes have been modelled as dynamic “valves” that rotate with the rotor. In this way the radial movements of the vanes are computed as a part of the simulation, based on the pressures due to the compression of the volumes on the inner diameter side of the vanes. The study is a result of collaboration between the University of Minnesota and the University of Naples “Federico II” research groups and the code developers of Simerics® Inc. The universities and Simerics® Inc. have all been involved in this project, working in close cooperation for the model building and simulations.

Stabilization of the Speed of the Hydraulic Motor Through Throttle Compensation for Volume Losses

2020 ◽  
Vol 26 (3) ◽  
pp. 126-130
Author(s):  
Krasimir Kalev
Keyword(s):  
Flow Rate ◽  
Hydraulic Drive ◽  
Pressure Change ◽  
Operating Conditions ◽  
Drive System ◽  
Inlet Pressure ◽  
Schematic Diagram ◽  
Hydraulic Characteristics ◽  
Hydraulic Motor ◽  
Flow Through

AbstractA schematic diagram of a hydraulic drive system is provided to stabilize the speed of the working body by compensating for volumetric losses in the hydraulic motor. The diagram shows the inclusion of an originally developed self-adjusting choke whose flow rate in the inlet pressure change range tends to reverse - with increasing pressure the flow through it decreases. Dependent on the hydraulic characteristics of the hydraulic motor and the specific operating conditions.

scholarly journals Parameter Estimation of a Countershaft Brake for Heavy-Duty Vehicles with Automated Mechanical Transmission

Processes ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 1036
Author(s):  
Yunxia Li ◽  
Lei Li
Keyword(s):  
Parameter Identification ◽  
Least Squares ◽  
Dynamic Model ◽  
Control Flow ◽  
Mechanical Transmission ◽  
Equivalent Resistance ◽  
Heavy Duty ◽  
Characteristic Parameters ◽  
Resistance Torque ◽  
Heavy Duty Vehicles

A countershaft brake is used as a transmission brake (TB) to realize synchronous shifting by reducing the automated mechanical transmission (AMT) input shaft’s speed rapidly. This process is performed to reduce shifting time and improve shifting quality for heavy-duty vehicles equipped with AMT without synchronizer. To improve controlled synchronous shifting, the AMT input shaft’s equivalent resistance torque and the TB’s characteristic parameters are studied. An AMT dynamic model under neutral gear position is analyzed during the synchronous control interval. A dynamic model of the countershaft brake is discussed, and its control flow is given. The parameter identification method of the AMT input shaft’s equivalent resistance torque is given on the basis of the least squares algorithm. The parameter identification of the TB’s characteristic parameters is proposed on the basis of the recursive least squares method (RLSM). Experimental results show that the recursive estimations of the TB’s characteristic parameters under different duty cycles of the TB solenoid valve, including brake torque estimation, estimation accuracy, and braking intensity estimation, can be effectively estimated. The research provides some reliable evidence to further study the synchronous shifting control schedule for heavy-duty vehicles with AMT.

scholarly journals Theoretical background of hydraulic drive control system analysis for testing piston hydraulic cylinders

2019 ◽  
Vol 19 (3) ◽  
pp. 242-249 ◽  
Author(s):  
A. T. Rybak ◽  
I. K. Tsybriy ◽  
S. V. Nosachev ◽  
A. R. Zenin
Keyword(s):  
Mathematical Modeling ◽  
Hydraulic System ◽  
Energy Recovery ◽  
Test Bench ◽  
Hydraulic Drive ◽  
Mechanical Transmission ◽  
Hydraulic Motor ◽  
Hydraulic Machines ◽  
Life Tests ◽  
Hydraulic Cylinders

Introduction. The durability and performance of hydraulic machines is determined through life tests. At that, various braking devices (mechanical, electric, hydraulic, etc.) are used for strength loading of the hydraulic motor, as a result of which a significant amount of energy is lost. This can be avoided if the method of rotational motion with energy recovery is used during life tests. This approach is applicable for hydraulic pumps, motors, and hydraulic cylinders.Materials and Methods. A test bench is presented, the design of which provides recreation of the conditions most appropriate for the field operation of hydraulic cylinders. In this case, energy recovery is possible. To solve the research problems, methods of mathematical modeling were used, the basic functional parameters of the proposed design were calculated. The determination of the pressure increment at various points in the hydraulic system is based on the theory of volumetric rigidity. When modeling the motion of the moving elements of the bench hydraulic system, the laws of rotor motion are used.Research Results. In the structure of the test bench, the cylinders in question are located in the pressure main between the hydraulic pump and the hydraulic motor. This enables to significantly reduce the bench itself and to save a significant amount of energy due to its recovery. A basic hydraulic diagram of the test bench for piston hydraulic cylinders is presented, in which the operation of the moving elements of the system is shown. A mathematical modeling of the hydraulic system of the bench is performed. A kinematic diagram of the mechanism for transmitting motion between test cylinders is shown.Discussion and Conclusions. The system of equations presented in the paper shows how the increment of pressure at the selected nodal points of the energy recovery system is determined (in particular, how the increment depends on time, reduced coefficient of volumetric rigidity, operating fluid consumption, and piston areas). The velocities of the hydraulic pistons are determined according to the kinematic scheme of the mechanical transmission of the bench. Thus it can be argued that, thanks to the solution presented in the paper, the life test results of hydraulic cylinders will adequately reflect their operation under rated duties.

scholarly journals Relative Susceptibility Among Alternative Host Species Prevalent in the Great Plains to Wheat streak mosaic virus

Plant Disease ◽  
2012 ◽  
Vol 96 (8) ◽  
pp. 1185-1192 ◽  
Author(s):  
D. Ito ◽  
Z. Miller ◽  
F. Menalled ◽  
M. Moffet ◽  
M. Burrows
Keyword(s):  
Mosaic Virus ◽  
Great Plains ◽  
Transmission Efficiency ◽  
Wheat Streak Mosaic Virus ◽  
Viral Reservoir ◽  
Grass Species ◽  
Mechanical Transmission ◽  
Weed Species ◽  
Crop Species ◽  
Jointed Goatgrass

Wild grasses, crops, and grassy weeds are known to host Wheat streak mosaic virus (WSMV) and its vector, the wheat curl mite (WCM). Their relative importance as a source of WSMV was evaluated. A survey of small-grain fields throughout Montana was conducted between 2008 and 2009. Cheatgrass was the most prevalent grassy weed and the most frequent viral host, with 6% infection by WSMV in 2008 (n = 125) and 15% in 2009 (n = 358). By mechanically inoculating plants with WSMV in the greenhouse, the highest susceptibility was found in rye brome (52.1%), jointed goatgrass (80.9%), and wild oat (53.9%. Quackgrass, not previously reported as a host, was susceptible to WSMV (12.7%). Mite transmission efficiency from susceptible grass species was lower than from wheat, and grass species must be a host for both WSMV and the WCM to serve as a virus source. WCM transmission was more efficient than mechanical transmission. Overall, results indicate that grass species can serve as a viral reservoir, regional variation in a weed species' susceptibility to WSMV cannot explain geographic variation in epidemic intensity, and crop species and closely related weeds (e.g., jointed goatgrass) remain the best reservoirs for both WSMV and the WCM.

Simulation on Displacement Characteristics of Variable Displacement of Double-Action Vane Pump

2010 ◽  
Vol 152-153 ◽  
pp. 1088-1091
Author(s):  
Lei Chen ◽  
Pan Zhang
Keyword(s):  
Simulation Model ◽  
High Speed ◽  
Steering System ◽  
Vane Pump ◽  
Hydraulic Power ◽  
Power Steering ◽  
Simulink Simulation ◽  
Variable Displacement ◽  
Hydraulic Power Steering System ◽  
Hydraulic Power Steering

On of the practical difficulties of high speed automotive hydraulic power steering is that the output exceeds the actual demands of the system, i.e., there is a substantial power loss. This paper discusses the configuration and the action principle of a new variable displacement of double-action vane pump, which consists of floating blocks. The pump belongs to an automotive hydraulic power steering system, and prosperous utilization is expected. In the meantime the mathematical and simulation model for hydraulic power steering of automobile were established and the Matlab Simulink simulation model was presented. Different parameters of pump are selected in simulating programming. The simulating results are analyzed and compared.

The Kinematical Analysis of the Hydraulic Motor With Swinging Bevel Gears

2008 ◽  
Author(s):  
Huran Liu
Keyword(s):  
High Efficiency ◽  
Flow Distribution ◽  
Basic Structure ◽  
Fundamental Principle ◽  
Hydraulic Motor ◽  
Low Velocity ◽  
Bevel Gears ◽  
Construction Mechanics ◽  
Oil Flow ◽  
Total Structure

A new kind of hydraulic motor suitable for the low velocity, large torque, high efficiency and mutable velocity output have been researched and developed in this paper. There are a series of creations, such as, the oil flow distribution, the principle of reducer, the output mechanics and the total structure. It features in the simple in construction, small of size, large ratio of reducer, high f ratio of torque-power, and low in energy consumption. It is suitable for all the occasions with hydraulic supply and all the fields when low velocity, large torque, high efficiency and mutable velocity output ware needed. Such as the construction mechanics, ship mechanics, heavy machine tool, heavy capstan and so on. The frequency of the hydraulic system is about 1000–2000/min, the reduced ratio of the planetary drive of swinging bevel gear is about 20–100, with 150 the maximum. This paper introduced the fundamental principle of the transmission of this mechanics, designed the basic structure of this mechanics, and analyzed the movement and forces.

A Study of the Internal Forces in a Variable-Displacement Vane-Pump—Part II: A Parametric Study

1986 ◽  
Vol 108 (2) ◽  
pp. 233-237 ◽  
Author(s):  
A. M. Karmel
Keyword(s):  
Parametric Study ◽  
Analytical Study ◽  
Design Criterion ◽  
Vane Pump ◽  
Continuous Components ◽  
Variable Capacity ◽  
Variable Displacement Vane Pump ◽  
Variable Displacement ◽  
Internal Forces ◽  
Line Pressure

This is the second part of an analytical study of the internal forces in a variable-displacement vane-pump. It presents a parametric study of the forces and torques applied to the mechanism and the shaft of this pump, as functions of line pressure, the eccentricity, and the design geometry. It is shown that the continuous components of the torque and of the direction of the radial shaft-load vary as a sawtooth wave at twice the vane-frequency while the magnitude of the radial shaft-load varies as a square wave at vane-frequency. The design criterion developed in the first part of this study is used to demonstrate the elimination of the magnitude variations in the radial shaft-load. The intermittent components of the internal forces vary as a pulse train at vane frequency and may produce high-peak pressure pulses which must be closely controlled. The variable-capacity feature of variable-displacement vane-pumps has a significant effect on the torque applied to the mechanism, but only a secondary effect on the overall radial shaft-load.

scholarly journals Reliability analysis on the drive system of a gear-type oil pump with variable displacement

2016 ◽  
Vol 8 (3) ◽  
pp. 168781401663880 ◽  
Author(s):  
Xiaolan Wang ◽  
Xubing Liu ◽  
Yansong Wang ◽  
Xintian Liu ◽  
Hui Guo
Keyword(s):  
Reliability Analysis ◽  
Drive System ◽  
Oil Pump ◽  
Variable Displacement
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