Geometric and Kinematic Modeling of a Variable Displacement Hydraulic Bent-Axis Piston Pump

2010 ◽  
Vol 5 (4) ◽  
Author(s):  
Mohammad Abuhaiba ◽  
Walter W. Olson
Keyword(s):  
Dynamic Model ◽  
Geometric Model ◽  
Main Shaft ◽  
Kinematic Modeling ◽  
Hydraulic Hybrid ◽  
Frequency Domains ◽  
Dynamic Forces ◽  
Angular Velocities ◽  
Variable Displacement ◽  
Hydraulic Hybrid Vehicle

One of the problems of a hydraulic hybrid vehicle (HHV) reported from testing by EPA is that the noise levels emitted by the hydraulic system are not acceptable. The pump is the main source of noise in HHV systems. However, the lack of space, the high pressure, and the dynamics of components within the pump have prevented either direct observation or measurement of potential noise causing mechanisms within the pump structure. As a result, there are several theories as to the source of the noise from the pump units but little concrete information to further isolate and reduce the noise generation. In this paper, a kinematic and a geometric model of a bent-axis pump have been created as part of a complete dynamic model. The other elements of the complete dynamic model that are not discussed in this paper include finding the variation of piston pressure, flow rate, and dynamic forces acting on the pump components as a function of angular rotations of both the main shaft and the yoke in the time and frequency domains. These elements address the harmonics of the forces acting on the case of the pump and will be presented in a future paper. The model was constructed using MATHEMATICA™ software and verified against very well known conditions of the motion of the main shaft and the yoke. It was found that the model predicted the variations of the angular velocities and accelerations of the entire pump’s parts starting from the main shaft to the yoke.

Predictive Energy Management for Parallel Hydraulic Hybrid Passenger Vehicle

2010 ◽  
Author(s):  
Timothy O. Deppen ◽  
Andrew G. Alleyne ◽  
Kim A. Stelson ◽  
Jonathan J. Meyer
Keyword(s):  
Energy Management ◽  
Hybrid Vehicle ◽  
Management Problem ◽  
Transfer Energy ◽  
Hybrid Powertrain ◽  
Engine Torque ◽  
Engine Simulation ◽  
Hydraulic Hybrid ◽  
Displacement Pump ◽  
Hydraulic Hybrid Vehicle

In this paper, a model predictive control (MPC) approach is presented for solving the energy management problem in a parallel hydraulic hybrid vehicle. The hydraulic hybrid vehicle uses variable displacement pump/motors to transfer energy between the mechanical and hydraulic domains and a high pressure accumulator for energy storage. A model of the parallel hydraulic hybrid powertrain is presented which utilizes the Simscape/Simhydraulics toolboxes of Matlab. These toolboxes allow for a concise description of the relevant powertrain dynamics. The proposed MPC regulates the engine torque and pump/motor displacement in order to track a desired velocity profile while maintaining desired engine conditions. In addition, logic is applied to the MPC to prevent high frequency cycling of the engine. Simulation results demonstrate the capability of the proposed control strategy to track both a desired engine torque and vehicle velocity.

scholarly journals A Transient Dynamic Model of Brake Corner and Subsystems for Brake Creep Groan Analysis

2017 ◽  
Vol 2017 ◽  
pp. 1-18 ◽  
Author(s):  
Dejian Meng ◽  
Lijun Zhang ◽  
Jie Xu ◽  
Zhuoping Yu
Keyword(s):  
Dynamic Model ◽  
Vehicle Body ◽  
Flexible Body ◽  
Stick Slip ◽  
Transient Dynamic ◽  
Numerical Studies ◽  
Slipping Friction ◽  
Frequency Domains ◽  
Rigid Body Simulation ◽  
Stick Slip Motion

To improve the understanding of brake creep groan, both experimental and numerical studies are conducted in this paper. Based on a vehicle road test under the condition of downhill, complicated stick-slip type motion of caliper and its correlation with the interior noise were analyzed. In order to duplicate these brake creep groan phenomena, a transient dynamic model including brake corner and subsystems was established using finite element method. In the model, brake components were considered to be flexible body, and the subsystems including driveline, suspension, tire, and vehicle body were considered to be rigid body. Simulation and experimental results of caliper vibration in time and frequency domains were compared. It was demonstrated that the new model is effective for the prediction and analysis of brake creep groan, and it has higher accuracy compared to the previous model without the subsystems. It is also found that the lining and caliper not only have stick-slip motion in each coordinate direction but also have translational and torsional movements in plane, which relate to the microscopic sticking and slipping, friction coefficient, and forces, as well as the contact status at the friction interface.

Simulation Investigations of Influence of Tooth Depth Coefficient on Dynamic Phenomena in Toothed Gear

2016 ◽  
Vol 817 ◽  
pp. 41-46
Author(s):  
Grzegorz Peruń
Keyword(s):  
Dynamic Model ◽  
Point Of View ◽  
General Level ◽  
Theoretical Point ◽  
Gear Pair ◽  
Contact Ratio ◽  
Dynamic Forces ◽  
Toothed Gears ◽  
Dynamic Phenomena

The increase of transverse contact ratio (εα) value usually allows reducing general level of gear vibroactivity. Article put to the test influence of coefficient εα value on dynamic forces in mesh zone with use of dynamic model of toothed gear. From theoretical point of view, the optimum value of transverse contact ratio is equal 2, what mean, that in mesh are always two pair of teeth. Obtainment such value of coefficient εα requires another construction of toothed wheels – wheels with HCR (High Contact Ratio) profile teeth. On result of occurrence of different deviations in toothed gears, as well as the dynamic phenomena, obtainment of continuous two-pair cooperation of gear pair is impossible and when this necessary is, solutions with near or exceed optimum value of coefficient are applied.

scholarly journals Simulation Study of Advanced Variable Displacement Engine Coupled to Power-Split Hydraulic Hybrid Powertrain

2009 ◽  
Author(s):  
Fernando Tavares ◽  
Rajit Johri ◽  
Zoran Filipi
Keyword(s):  
Hybrid Powertrain ◽  
Cylinder Deactivation ◽  
Integrated Simulation ◽  
Engine Model ◽  
Hydraulic Hybrid ◽  
Wide Range ◽  
Power Split ◽  
Variable Displacement ◽  
Mode Transitions ◽  
And Control

The simulation-based investigation of the variable displacement engine is motivated by a desire to enable unthrottled operation at part load, and hence eliminate pumping losses. The mechanism modeled in this work is derived from a Hefley engine concept. Other salient features of the proposed engine are turbocharging and cylinder deactivation. The cylinder deactivation combined with variable displacement further expands the range of unthrottled operation, while turbocharging increases the power density of the engine and allows downsizing without the loss of performance. While the proposed variable displacement turbocharged engine (VDTCE) concept enables operations in a very wide range, running near idle is impractical. Therefore, the VDTCE is integrated with a hybrid powertrain allowing flexibility in operating the engine, elimination of idling and mitigation of possible issues with engine transients and mode transitions. The engine model is developed in AMESim using physical principles and 1-D gas dynamics. A predictive model of the power-split hydraulic hybrid driveline is created in SIMULINK, thus facilitating integration with the engine. The integrated simulation tool is utilized to address design and control issues, before determining the fuel economy potential of the powertrain comprising a VDTCE engine and a hydraulic hybrid driveline.

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