scholarly journals The selection of the tail lift parameters

2019 ◽  
Vol 20 (1-2) ◽  
pp. 364-367 ◽  
Author(s):  
Łukasz Warguła ◽  
Bartosz Wieczorek ◽  
Mateusz Kukla

People moving on wheelchairs overcome the forces of resistance such as: air resistance, resistance of the ascent, inertia force and rolling resistance force. Under certain conditions of use of the wheelchair, the only resistance that must overcome the driving force during the movement is the rolling resistance force. This situation occurs during uniformly rectilinear movement, on a flat level surface at speeds of up to 20 km/h, because at this speed the air resistance is negligible. Rolling resistance is mainly influenced by the mass of the rolling object and the rolling resistance coefficient of the running gear. The value of the rolling resistance coefficient can be influenced, among others, by the surface, type and level of pressure in the tire, and the measurement method. There are test methods that in the resistance of rolling beyond the resistance resulting from the contact of the tire with the surface take into account the resistance to connection of the wheel with the driven object. One of them is the innovative method of measuring the rolling resistance coefficient of objects equipped only with the running gear according to the patent application P.424484 and the developed device for these tests in accordance with the patent application P.424483. The article presents the results of wheelchair rolling resistance test with a classic drive system and wheel attachment. These results show differences in the aspect of rolling resistance of classic wheelchairs with wheelchairs equipped with innovative propulsion solutions, such as a lever drive system or a hybrid drive. The study was financed from the means of the National Centre for Research and Development under LIDER VII programme, re-search project no. LIDER/7/0025/L-7/15/NCBR/2016.

2019 ◽  
Vol 20 (1-2) ◽  
pp. 360-363 ◽  
Author(s):  
Łukasz Warguła ◽  
Mateusz Kukla ◽  
Bartosz Wieczorek

The basic resistance during moving objects that are equipped with a circular system is rolling resistance. In objects powered by muscle power, such as: bicycles, wheelchairs, mobile machines, shelves and storage trolleys, the problem of rolling resistance limitation is more important than in the case of structures powered by engines characterized by a significant excess of driving force relative to the sum of resistance forces. Research is being carried out on limiting the rolling resistance force, however, there is a lack of methods for measuring this parameter in the actual operating conditions of devices with a drive system without a drive unit. In the article for research, an innovative method was used of measuring the rolling resistance coefficient of objects equipped only with the rolling chassis of accordance with the patent application P.424484 and a test device compatible with the patent application P.424483. The study involved a pneumatic wheel commonly used in wheelchairs, the use of which gains popularity with increased interest in the construction of electric or diesel vehicles with low energy demand. Examples of such vehicles are available during the Shell Eco-marathon competition. The study was financed from the means of the National Centre for Research and Development under LIDER VII programme, research project no. LIDER/7/0025/L-7/15/NCBR/2016.


2019 ◽  
Vol 254 ◽  
pp. 01005 ◽  
Author(s):  
Łukasz Wargula ◽  
Bartosz Wieczorek ◽  
Mateusz Kukla

Rolling resistance coefficient is one of the basic resistance when moving objects. In case of objects not equipped with a motor-driven wheels and suspension system , such as: wheelchairs, mobile machinery chopper, shelving and warehouse trucks all resistances are overcome by the muscle strength of the operator. Research is carried out to limit this phenomenon, however, there is a lack of methods for measuring this parameter in the real operating conditions of devices with a wheels and suspension system without a drive unit. The article presents an innovative method of measuring the rolling resistance coefficient of objects equipped only with the wheels and suspension system accordant with the patent application P.424484 and the developed device for these tests in accordance with patent application P.424483. Additionally, the paper presents the results of preliminary tests on the measurement of pivoting coefficient of a transport truck loaded with a given mass.


2018 ◽  
Vol 19 (12) ◽  
pp. 256-259
Author(s):  
Piotr Wrzecioniarz ◽  
Wojciech Ambroszko ◽  
Aleksandra Pindel

In the paper limitations and exemplary methods of rolling resistance minimization are described. Changes of value of rolling resistance coefficient during years and values for exemplary rolling pairs are presented. Conclusions about future progress are formulated.


2020 ◽  
Author(s):  
Sutisna Nanang Ali

This study presents rolling resistance estimation in the design process of passenger car radial (PCR) tyre by using finite element method. The rolling resistance coefficient of tyres has been becoming one of main requirements within the regulation in many countries as it is related to the level of allowable exhaust gas emission generated by vehicle. Therefore, the tyre being designed must be digitally simulated using finite element method before the tyre is manufactured to provide a high confident level and avoid unnecessary cost related to failure physical product testing. The simulation firstly computes the deformation of several alternative designs of tyres under certain loading, and then the value of deformation force in each tyre component during deformation took place is calculated. The total force of deformation is considered as energy loss or hysteresis loss resulted in tyre rolling resistance. The experiment was carried out on three different tyre designs: two grooves, three grooves, and four grooves. The four groove tyre design gave the smallest rolling resistance coefficient (RRC). Finally, the simulation was continued to compare different crown radius of the tyres and the result shows that the largest crown radius generates the lowest rolling resistance.


Author(s):  
S P Rykov ◽  
V N Tarasuyk ◽  
V S Koval ◽  
N I Ovchinnikova ◽  
A I Fedotov ◽  
...  

2019 ◽  
Vol 254 ◽  
pp. 04007 ◽  
Author(s):  
Bartłomiej Pałasz ◽  
Konrad J. Waluś ◽  
Łukasz Warguła

Contemporary vehicle are designer to be eco-friendly. One of the factors limiting the energy consumption of driving processes is a low value of the rolling resistance coefficient. The rolling resistance depends on the construction features of a tire, exploitation conditions and the type of surface the car moves on. This article presents the results of experimental research of determining the rolling resistance coefficient with the use of laboratory method of roller test bench. The results presented here are a part of a wider research of determining the rolling resistance coefficient and the influence of research method on its value.


2011 ◽  
Vol 228-229 ◽  
pp. 60-65
Author(s):  
Hong Liang Lin ◽  
Qiang Yu ◽  
Xue Li Zhang

Vehicle’s sliding resistance mainly includes rolling resistance, air drag resistance and friction within the transmission, wheel bearings and other related components. Among those, rolling resistance and air drag always exist whenever vehicle is running, so they have great influence on vehicle’s dynamic performance and fuel economy. Therefore, it is important to determine vehicle’s rolling resistance coefficient and air drag coefficient quickly and accurately in order to operate vehicle properly and reduce the vehicle’s fuel consumption. Combining theoretical analysis with experimental verification, calculation model based on road coasting test was given by means of least squares principle. And through which vehicle rolling resistance coefficient and air drag coefficient were determined easily. Then by using the test data from some Minibus, the vehicle's rolling resistance coefficient and air drag coefficient are calculated according to established model. The computation result shows that rolling resistance coefficient is a linear function of the speed and the air drag coefficient is constant. Finally, the analysis shows that the calculation model is simple, precise and useful.


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