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Fundamentals of Earthmoving
Published in John E. Schaufelberger, Giovanni C. Migliaccio, Construction Equipment Management, 2019
John E. Schaufelberger, Giovanni C. Migliaccio
Rolling resistance is the resistance of the equipment operating surface to the forward or reverse movement of a piece of wheeled equipment as illustrated in Figure 6.1. It does not apply to tracked equipment, because the idler, rollers, and sprocket always run on steel track rails. It results from internal friction of the wheel bearings, tire flexing, and penetration of the operating surface due to the pressure of the tires. For example, loose sand or mud provide more rolling resistance than does a compacted clay surface, because of tire penetration into the sand or mud. Penetration is not necessary if the operating surface deflects under load. Rolling resistance is expressed in pounds of resistance per ton of gross vehicle weight. Gross vehicle weight is the weight of the piece of equipment without load plus the weight of any load that it is carrying. It varies with the size, air pressure, and tread of the tires and the condition of the operating surface.
Mechanistic modeling of macro-texture’s effect on rolling resistance
Published in A. Kumar, A.T. Papagiannakis, A. Bhasin, D. Little, Advances in Materials and Pavement Performance Prediction II, 2020
The road surface profile consists of various scales of roughness and texture which can affect different aspects of tire-pavement interaction such as rolling resistance, friction, noise, etc. Rolling resistance plays an important role in vehicle fuel consumption while friction is essential for safety of the vehicle. There is a good understanding of the effect of pavement surface texture on friction. However, the effect of surface texture on rolling resistance has only been investigated in a few studies.
Earthmoving, Excavating, and Lifting Equipment Selection
Published in Douglas D. Gransberg, Jorge A. Rueda-Benavides, Construction Equipment Management for Engineers, Estimators, and Owners, 2020
Douglas D. Gransberg, Jorge A. Rueda-Benavides
Rolling resistance is the resistance of a level surface to a uniform velocity motion across it. It is the force required to shear through or over a surface. An example is a truck tire developing friction on the road surface as it turns. Rolling resistance has two components. Surface resistance results from the equipment trying to roll over the travel surface material. Penetration resistance results from the equipment tires sinking into the surface. Obviously, this resistance will vary greatly with the type and condition of the surface over which the equipment is moving. Simply put, soft surfaces have a higher resistance than hard surfaces.
RESNA position on the application of ultralight manual wheelchairs
Published in Assistive Technology, 2023
Lynn A. Worobey, Jennith Bernstein, Joseph Ott, Theresa Berner, Jaqueline Black, Mary Cabarle, Tina Roesler, Sage Scarborough, Kendra Betz
Since rear wheels and tires make direct contact with the ground, they have an influence on ride characteristics, comfort, and rolling resistance. Rear wheels can be impacted by physical characteristics, style, and material properties. While the diameter is typically selected based on the requirements for push-rim access, a larger diameter tire will have a lower rolling resistance. Furthermore, smaller tire widths tend to have a lower rolling resistance, but the material compound that composes the tire is also a factor (Kauzlarich & Thacker, 1985). Tire pressure is inversely related to rolling resistance. High-pressure pneumatic tires (over 100 max psi) have been proven to have a lower rolling resistance than lower-pressure pneumatic tires (under 100 max psi), solid tires, or airless inserts (Ott et al., 2020).
Energy reduction by power loss minimisation through wheel torque allocation in electric vehicles: a simulation-based approach
Published in Vehicle System Dynamics, 2022
Juliette Torinsson, Mats Jonasson, Derong Yang, Bengt Jacobson
The rolling resistance power loss for the four tyres can be expressed as Rolling resistance is affected by a number of factors, e.g. structure of the tyre, operating conditions, normal load, tyre pressure and applied torque [18]. In Equation (4), the contribution of longitudinal force (indirectly applied torque) to rolling resistance moment is decided by the parameter . In most tyre measurements, it is neglected and set to zero. Literature has investigated this contribution [19–21] and it can be found that for a passenger tyre, take on the value of 0.015 for a bias belted tyre with 4000 N vertical load [19]. However, it is hard to know if this number is still relevant since passenger car tyres have been developed significantly since the study was conducted [22]. To the knowledge of the authors, there is no more recent study that has investigated this dependency, thus the value of 0.015 is used.
Measurement of rolling resistance and scrub torque of manual wheelchair drive wheels and casters
Published in Assistive Technology, 2022
Stephen Sprigle, Morris Huang, Jacob Misch
The caster rolling resistance data on tile present trends that both corroborate and conflict with the findings of prior assessments of rolling resistance. Rolling resistance forces fall within the same range found by Sauret (Sauret et al., 2012), but casters do not follow the trend of greater rolling resistance with decreasing diameter. This may be explained by this study’s smaller sample of components, which vary not only in diameter but also in tire width, profile, and hardness. All of these factors influence wheel contact surface which, in turn, influences rolling resistance (Kauzlarich & Thacker, 1985). Within the DW data, the two solid tires, the Primo XPRESS and Solid Mag, have greater rolling resistances compared to the pneumatic drive wheels, with the Solid Mag values especially pronounced (Tables 4 and Tables 5). This result matches well with the findings of a dynamometer-based rolling resistance study (Kwarciak et al., 2009), which found that the solid tires exhibited rolling resistances of 4–9 N while pneumatic tires exhibited rolling resistances of 2–3 N. The differences between their presented values and ours are likely due to their use of a dynamometer versus over-ground motion and due to the different contact surfaces.