MTZ K-744R1, Operating Instruction

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KIROVETS K-744R1, K-744R2, K-744R3, K-744R4 tractors
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The gearbox is mechanical, multi-stage, four-regime, with constant-mesh gears, with a
mechanical regime change drive and hydraulic gear change without break of the power flux
within any of regimes. It allows to change the tractor motion speed, implement motion by back
running, engage the rear driving axle, transmit torque to the power take-off (PTO) as well as
ensure driving of the steering control pump from the wheels during tractor towing with faulty
engine. Four lifting eye-nuts are installed in the upper lid of the gearbox for installation and
dismantling of the latter. A lifting eye-bolt is installed on the PTO coupling housing for the
execution of similar operations.
The cardan driv e consists of a cardan shaft of the gearbox, cardan shaft of the front axle,
intermediate shaft of the rear axle, intermediate support and cardan shaft of the rear axle.
The intermediate support connects the cardan shafts transmitting the torque from the transfer
shaft of the gearbox to the rear axle.
Both tractor axles are driving and serve for increase of the torque to be driven to them from
the gearbox and for its transfer to the wheels. On the tractors, the front driving axles are
suspended to the frame on two semi-elliptic carriage springs with telescopic hydraulic shock
absorbers.The rear axles of all tractors are fastened rigidly to the frame.
The service brakes are dry, of block type, with a separate pneumatic drive to the front and rear
wheels, are installed in the rear-axle drives of the leading axles.
The parking brake is with spring energy accumulators combined with the service pneumatic
chambers of the front and rear axles.
On both leading axles , wheels with low-pressure tyres are installed.Tyres 28,1R-26 of model
ФД-12 are installed on K-744R1 tractors; tyres30,5R-32 of model Ф-81 are installed on K-
744R2, K-744R3, K-744R4 tractors.
The tractor turn control system is with a power drive.
The tractor turn is performed by means of two hydraulic cylinders due to swinging the tractor
semi-frames in respect of each other around the vertical hinge pivot. On new tractors, the total
free play in the connections of “hydraulic cylinder – semi-frame lifting eyes” (over the hydraulic
cylinder axis) can be no more than 0.9 mm.The permissible total free play in the course of
operation shall not exceed 1.8 mm. The feed of working fluid to the hydraulic cylinders, which is
proportional to the angle of turn and the rotational speed of the steering wheel, is performed by
the steering m
echanism РМ 2000 installed on the steering column.
A pump with adjustable flow-rate is installed in the hydraulic system of the operating equipment.
Two pressure filters provide cleaning of the working fluid to be fed from the pumps to the
hydraulic system units.