Technical support

Determining technical parameters of coupling systems in agricultural vehicles:

  • General info

1. Firstly, select the type of the trailer to be towed. If the type is not specified, which means both trailers with the first steering axle and centre-axle trailers will be towed, then couplings adapted for centre-axle trailers should be used (they can be burdened with vertical loads)
2. The parameters specified for the specific case must be lower than the new coupling used or the drawbar tip, fifth-wheel coupling!
For example: in the calculations for the D parameter, D = 100 kN has been determined
For hitch, drawbar tip and the fifth wheel, the D parameter must be greater than 100 kN!

When replacing the existing hitch into a hitch of the different brand, particular attention should be paid to:
 - mounting method - location of the mounting holes, which are standardised and always specified in the table next to the type of coupling
 - parameters of the new coupling must be higher or equal to the replaced one

Hitching systems approved in accordance with EU Directive 94/20/EC. The parameters on the nameplate (D, Dc, S, V, U) are consistent with those obtained during the certification.
1. value of D: theoretical pulling power indicator that defines the hypothetical dynamic horizontal force between a towing vehicle and a trailer with front steering axle (no vertical load on the hitch!)
2. value of Dc: theoretical pulling power indicator that defines the hypothetical dynamic horizontal force between a towing vehicle and a centre-axle trailer (vertical load on the hitch is present!)
3. value of V: theoretical pressure power indicator that defines the hypothetical dynamic vertical force between a towing vehicle and a centre-axle trailer with allowable total weight with a maximum mass over 3.5 tonnes (dynamic vertical force acting on heavy centre-axle trailers hitch)
4. value of S: static vertical force exerted on the hitch by centre-axle trailers in resting condition
5. wartość U: pionowe obciążenie wywierane na 5. value of U: vertical load exerted on the fifth wheel coupling by a  semi-trailerprzez naczepę

In case of any doubt do not hesitate to contact our office!

Determining the load parameters for hitches of heavy trucks/lorries and trailers drawbars:

 


where:
g = gravitational acceleration ; 9.81 m/s2;
T = vehicle allowable total weight in tonnes;
R = trailer allowable total weight in tonnes;

 

Determining the load parameters for centre-axle trailers

 


where:
T = vehicle allowable total weight in tonnes, including the vertical load at rest transmitted to the hitch by the drawbar tip ;
C = total maximum axle load transmitted to the ground by a trailer in tonnes;

where:
x = length of the cargo space in meters;
L = distance between the centre of the drawbar tip hole and the centre of the trailer axle distance in meters;
V = dynamic vertical load in kN
C = total maximum axle load transmitted to the ground by a trailer in tonnes;
A = 1,8 m/s2 for vehicles with air suspension or equivalent type of suspension
A = 2,4 m/s2 for vehicles with other types of suspension
R = trailer allowable total weight in tonnes ;

 

Determining the load parameters for fifth wheel couplings  and kingpins of the semi-trailer

 


where:
T = vehicle weight in tonnes, including the vertical fifth wheel coupling load
R = semi-trailer weight
U = semi-trailer fifth wheel coupling load

 

Important information about fifth wheel couplings 'maintenance-free, low-maintenance, with plastics", and so on.

Any questions? Any doubts?
Feel free to ask!

Hanna Motek

Logistyka / Faktury
(+48) 500 220 606
+48 61 894 43 10
zamowienia@orlandi.pl
Polish English русский

Leszek Izydorczyk

Konsultant handlowy
(+48) 731 03 03 03
+48 61 894 43 10
leszek.izydorczyk@orlandi.pl
Polish English

Daniel Piechocki

Konsultant handlowy
(+48) 518 955 114
+48 61 894 43 10
daniel.piechocki@orlandi.pl
Polish English

Fifth wheel couplings with sliding plastic inserts are continuously increasing its share of sales in the European market. This happens for many reasons, but the most important are: economics and ecology.

Why are the low maintenance couplings used?
- to reduce the amount of lubricant used;
- to extend the life of the fifth wheel coupling board;
- to reduce the adverse impact of trucks/lorries on the environment
- to extend the mileage between inspections of vehicles;
- to avoid damage to the semi-trailer flanged lift bearing;
- to allow for proper interaction of the fifth wheel coupling with a semi-trailer flanged lift bearing at high temperatures.

Costs, profits
Depending on the operating conditions, old grease should be removed from standard fifth wheel couplings and the new one should be applied ca. every 5000 to 20.000 km. For such lubrication, several kilograms of grease is consumed and it takes a half man-hour service. This operation costs always x zlotys (check your last bill). When low-maintenance couplings are used, these costs are not incurred (only the fifth wheel coupling lock is lubricated, the coupling lock can be connected to the central lubrication system). The low-maintenance fifth wheel coupling flanged lift bearings are typically replaced every 150 -200 thousand km depending on operating conditions. Replacement of plates is simple and fast (it involves removing 6 mounting screws, replacement of the flanged lift bearings into the new ones and mounting them).
To meet the needs of transportation companies, the V. Orlandi Company offers RP10, the low-maintenance version of fifth wheel couplings made of cast iron, for the same price as commonly lubricated RP10 couplings. The retail price of the sliding inserts is about PLN 300 net.

REMEMBER:
- take care of the environment;
- calculate the costs;
- save thanks to modern solutions from V. ORLANDI POLSKA.
- all spare parts, including flanged lift bearings, are always available in the distribution networks and in the V. Orlandi Company warehouse in Poland.

IMPORTANT:
- sliding inserts should not be lubricated
- to extend the life of low-maintenance couplings, the semi-trailer coupling plate and the flanged lift bearing must be kept clean (solid contaminants: sand, rust, and filings significantly accelerate the wear of couplings flanged lift bearings).

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