Prediction of Synchronization Time for Tractor Power-Shift Transmission Using Multi-Body Dynamic Simulation

2021 ◽  
Vol 64 (5) ◽  
pp. 1483-1498
Author(s):  
Hyun-Woo Han ◽  
Jung-Su Han ◽  
Woo-Jin Chung ◽  
Ji-Tae Kim ◽  
Young-Jun Park
Keyword(s):  
Automatic Transmission ◽  
Output Shaft ◽  
Analytical Equation ◽  
List Type ◽  
Drag Torque ◽  
Synchronization Time ◽  
Axial Forces ◽  
Power Shift ◽  
Body Dynamics ◽  
Multi Body

HighlightsPrediction of synchronization time was performed for a power-shift transmission.We derived an analytical equation for synchronization time and developed a multi-body dynamics model.Model results were compared with results of a power-shift test on a synchronizer.Reduced computation and design time was achieved for automatic transmission design.Abstract. Synchronization time determines the capacity of a shift actuator for an automatic transmission system. Existing approaches for measuring this time only consider one rotational inertia and therefore cannot be applied to the power-shift transmission (PST) of a tractor with wet multi-plate clutches on both sides of the synchronizer. This study aims to predict the PST synchronization time by considering time-varying axial forces as first-order functions and the equivalent rotational inertias of the hub and the gear. First, we derive an analytical equation for the synchronization time. We then develop a multi-body dynamics (MBD) model that includes the drag torque of the wet multi-plate clutches. The MBD model is composed of a synchronizer, a linkage, and an output shaft of a shift actuator as a rigid-body system. A power-shift test was performed on the synchronizer at two shift stages requiring the maximum shift force of the system. The torque of the shift actuator (the input of the shift system) and the angular displacement of the output shaft of the shift actuator (the output of the shift system) were measured. The results of the simulation model were then compared with those of the shift test. Compared with the test results, the simulation results were validated within 7.63% accuracy, based on the maximum value for the torque of the shift actuator. The proposed equation was validated within a maximum error range of 8.25%. The proposed equation did not consider drag torque of the wet multi-plate clutches because that torque is much smaller than the cone torque of the synchronizer in the target shift system. The proposed equation can reduce computation time and will enable more precise sizing of the synchronizer and shift actuator in the early design stages of automatic transmissions. Keywords: Multi-body dynamics, Power-shift transmission, Synchronization time, Synchronizer, Tractor transmission.

scholarly journals Tool Evaluation & Design Analysis for Parking Pawl Mechanism

2021 ◽  
Vol 9 (8) ◽  
pp. 1396-1403
Author(s):  
Amit R. Patil
Keyword(s):  
Electric Vehicles ◽  
Automatic Transmission ◽  
Rear Wheel ◽  
Front Wheel ◽  
Tool Evaluation ◽  
Automatic Transmissions ◽  
Vehicle Variant ◽  
Wheel Drive ◽  
Body Dynamics ◽  
Multi Body

Abstract: Automatic Transmissions in vehicles are becoming the norm today and with the need to reduce fuel consumption, electric vehicles are increasing in number too. As the vehicles get smarter, transmissions have also felt the need to adapt so as to cope with the demands of the 21st century. Apart from providing the user with different driving modes, vehicles with an Automatic Transmission and electric vehicles have a device called a Park Lock. Park Lock Mechanisms are devices that are fitted to vehicles with an automatic transmission or electric vehicles which can secure the vehicle mechanically in addition to the parking brakes to prevent an unintended movement of the vehicle when the vehicle is brought to a stop. This system can face various kinds of loads coming from the transmission or from the wheel side. So, it is necessary to design a system which can withstand against it. Today, when a park lock mechanism is designed, it is designed in a way that it not only fits one vehicle variant but many variants (these variants can include either front wheel drive, rear wheel drive, vehicles with varying final gear to park lock gear ratios etc). Therefore, one Park Lock Mechanism needs to satisfy various conditions and requirements. Carrying out calculations with different notations for each variant becomes a cumbersome procedure, therefore it is prudent to have one common platform which can do the calculation in the early phases of design. In this paper, a closed form calculationsbased Excel VBA tool can able to estimate the loads coming on to the Park lock mechanism by doing some background calculation is presented followed by the simulation performed using Multi Body Dynamics software (‘ADAMS’). Results from MBD tool and a 1D tool are corelated to the test data to gain some confidence on the tool which created in Excel VBA. Keywords: Park Lock Mechanism, ADAMS, 1D Tool, Excel VBA, Drop in Speed, Torque Build up.

scholarly journals Estimating maximum bite performance in Tyrannosaurus rex using multi-body dynamics

2012 ◽  
Vol 8 (4) ◽  
pp. 660-664 ◽  
Author(s):  
K. T. Bates ◽  
P. L. Falkingham
Keyword(s):  
Body Size ◽  
Feeding Behaviour ◽  
Ontogenetic Change ◽  
Positive Allometry ◽  
Musculoskeletal Models ◽  
Terrestrial Animal ◽  
Body Dynamics ◽  
Mode Of Life ◽  
Scaling Analyses ◽  
Multi Body

Bite mechanics and feeding behaviour in Tyrannosaurus rex are controversial. Some contend that a modest bite mechanically limited T. rex to scavenging, while others argue that high bite forces facilitated a predatory mode of life. We use dynamic musculoskeletal models to simulate maximal biting in T. rex . Models predict that adult T. rex generated sustained bite forces of 35 000–57 000 N at a single posterior tooth, by far the highest bite forces estimated for any terrestrial animal. Scaling analyses suggest that adult T. rex had a strong bite for its body size, and that bite performance increased allometrically during ontogeny. Positive allometry in bite performance during growth may have facilitated an ontogenetic change in feeding behaviour in T. rex , associated with an expansion of prey range in adults to include the largest contemporaneous animals.

Sir Robert Stawell Ball and methodologies of modern screw theory

2002 ◽  
Vol 216 (1) ◽  
pp. 1-11 ◽  
Author(s):  
H Lipkin ◽  
J Duffy
Keyword(s):  
Computational Geometry ◽  
Rigid Body ◽  
Lie Algebra ◽  
Screw Theory ◽  
Mechanical Design ◽  
Ball Screw ◽  
Dual Numbers ◽  
Body Dynamics ◽  
Rigid Body Mechanics ◽  
Multi Body

The theory of screws was largely developed by Sir Robert Stawell Ball over 100 years ago to investigate general problems in rigid body mechanics. Nowadays, screw theory is applied in many different but related forms including dual numbers, Plilcker coordinates and Lie algebra. An overview of these methodologies is presented along with a perspective on Ball. Screw theory has re-emerged after a hiatus to become an important tool in robot mechanics, mechanical design, computational geometry and multi-body dynamics.

Tanker Truck Sloshing Simulation Using Bi-Directionally Coupled CFD and Multi-Body Dynamics Solvers

2014 ◽  
Author(s):  
Michael S. Barton ◽  
David Corson ◽  
John Quigley ◽  
Babak Emami ◽  
Tanuj Kush
Keyword(s):  
Body Dynamics ◽  
Tanker Truck ◽  
Multi Body

Study of Self-Propelled Pufferfish Driven by Multiple Fins: A Comparison Between Rigid and Deformable Fins

2017 ◽  
Author(s):  
Ruoxin Li ◽  
Qing Xiao ◽  
Lijun Li ◽  
Hao Liu
Keyword(s):  
Underlying Mechanism ◽  
Operating Conditions ◽  
The Self ◽  
Fish Swimming ◽  
Propulsion Efficiency ◽  
Live Fish ◽  
Body Dynamics ◽  
Computational Fluid Dynamics Cfd ◽  
Multi Body ◽  
Better Than

In this work, we numerically studied the steady swimming of a pufferfish driven by the undulating motion of its dorsal, anal and caudal fins. The simulations are based on experimentally measured kinematics. To model the self-propelled fish swimming, a Computational Fluid Dynamics (CFD) tool was coupled with a Multi-Body-Dynamics (MBD) technique. It is widely accepted that deformable/flexible or undulating fins are better than rigid fins in terms of propulsion efficiency. To elucidate the underlying mechanism, we established an undulating fins model based on the kinematics of live fish, and conducted a simulation under the same operating conditions as rigid fins. The results presented here agree with this view by showing that the contribution of undulating fins to propulsion efficiency is significantly larger than that of rigid fins.

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