The transfer number of the synchronizing reducer gets out so that the torque was transferred to semi-trailer wheels, when slipping wheels of a tractor more than four percent. At smaller slipping of wheels of a tractor of the semi-trailer wheels of the semi-trailer are conducted. Thus, at the movement of the car on the dense soil providing big coefficient of coupling, the torque is transferred only to forward wheels of the car, and at the expense of symmetric differential the torque is transferred evenly to both wheels, and in this case the traction effort is provided by only forward wheels. At the movement on off road terrain when the coefficient of coupling with soil decreases, and slipping increases, the torque is distributed on all wheels of the lesotransportny car.
The active semi-trailer consists of two semi-frames of the connected by the universal hinge, average and back leading bridges and wheels. The forward semi-frame rigidly fastens to the tractor case. On a back semi-frame the leading bridges with brakes and final transfers are mounted.
Along with advantages, these transfers have a number of essential shortcomings: decrease in efficiency of transmission at big ranges of regulation and, as a result, diseconomy of long operation of the machine on the modes which are not corresponding to rated loads; a little big mass of transmission on unit of the transferred power; higher cost of transmission.
The car is intended for a podtaskivaniye, collecting, loading, on the fad of trees or switches, skidding of a pack of trees in the semi-shipped state, unloading and an earthing up of trees on the top lesosklad of forestries and forest complex enterprises.
Receiving finished goods is connected with performance of a certain technological process. Technological process of the logging enterprise is very difficult and proceeds in various conditions that causes the necessity of creation of the special equipment for preparation and transportation of forest products.
The lesotransportny machine designed in this degree project, on the basis of the agricultural T-25A1 tractor with the active semi-trailer, possesses many of the listed above advantages and has to find application in the logging industry.
It is developed by Kirov Plant together with TsNIIME, it is timber industry modification of the agricultural K-700A tractor of a class of draft 5 and represents the basic chassis intended for installation on it various processing equipment. The tractor has tires of the increased loading capacity, on a back semi-frame places for installation of processing equipment are provided.
The fourth direction of creation of forest wheel cars was widely adopted. Now by such principle prototypes on the basis of serial agricultural tractors are made. Cars successfully passed test.