Belarus 892 - Ways of Changing Tractor Grip Characteristics and Passability; General Information

892-0000010B OM
210
5.7 Ways of changing tractor grip characteristics and passability
5.7.1 General information
BELARUS-892/892.2 tractors perform the majority of technological processes in agri-
cultural production in motion by way of direct implement and instrument towing by means of
pneumatic wheel tyres’ grip with ground area. Tractive force developed at wheel rim is linearly
proportional to the tractor adhesive weight. That is why under certain conditions with increase
of tractor’s operating weight, its tractive characteristics increase.
BELARUS-892/892.2 tractors are designed for operation with certain values of weight
loads on tractor framework and undercarriage. Fulfillment of recommendations for additional
ballasting depending on operating conditions ensures the possibility of safe and proper op-
eration without critical tractor overloads for at least the specified service life.
The limit of increase in the adhesive weight is, in fact, the permissible load on the
tyres, which depends on the tyre size and internal pressure. In this case, the manufacturer
establishes the permissible maximum loads on the rear axle and the front axle of the tractor
at the maximum travel speed in transport mode.
Note - Air pressure standards in the front and rear tyres of BELARUS-892/892.2 trac-
tors with the current load and speed are given in subsection 4.2.8 “Selecting of optimal inner
pressure in tyres depending on operational conditions and load on tractor axles, instructions
for use of tyres.”
Gripping features and terrain performance of BELARUS-892/892.2 tractors in specific
operating conditions depend on the following factors:
- tractor adhesive weight and ballast used in a specific tractor configuration;
- distribution of weight of tractor, ballast and implement in the tractor unit along tractor
axles;
- size of and pressure in tyres used;
- technical condition and workability of tractor undercarriage system;
- proper and timely application of recommendations of manufacturing plant for en-
hancement of tractor tractive characteristics;
- condition and properties of ground area;
- wheel tyres grip factor with ground area;
A limiting factor in the use of agricultural tractor is the terrain that is characterized by
steepness and configuration of the cultivated areas of the field, as well as their altitude above
sea level. Other iInfluencing factors of cultivated area of the field altitude are atmospheric
pressure and ambient temperature. The engine power is reduced by 1,0 % for each 100.0m
of altitude above sea level, while fuel consumption increases to the same extent.
BELARUS-892/892.2 tractors are intended primarily for lowland conditions, and for lim-
ited use, subject to safety measures and recommendations, in areas with a significant steep-
ness of the slopes with altitude above sea level.
Changing of BELARUS-892/892.2 tractors terrain performance and gripping charac-
teristics by means of increasing the operating weight within permissible limits is most effec-
tive in the conditions, when bearing power of soil grows up with increasing track depth. For
example, with tractor weight increase due to additional ballasting on stubble of winter crops
on mineral soils, the tractive power of tractor on the hook increases by 8.8 … 28.3 %, de-
pending on soil moisture.