Power take-off (PTO) - single-stage, attached to the gearbox housing on the right side and designed to drive auxiliary units
The box is made in two versions: with a pump (Fig. 1) and a flange (Fig. 2).
Turn on the power take-off when the air pressure in the vehicle's pneumatic system is at least 500 kPa (5 kgf/cm2) and the clutch is disengaged.
Adjusting shims are installed between the flanges of the gearbox and power take-off housings, with the help of which the lateral clearance in the gear engagement is adjusted (according to noise).
If it is necessary to replace the gaskets with new ones, their thickness must be maintained.
Power take-off control, pneumatic, consists of a control valve, a switching mechanism and air ducts.
To ensure remote activation of the power take-off in the cab, to the right of the driver, on the lower edge of the instrument panel, a control valve is installed on the bracket.
When the power take-off is off lever 8 (Fig. 3) is in the upper position, stem 7 is in the right position.
The valve 3 under the action of the spring 2 is pressed against the village 4 and the air does not flow through the valve.
When the power take-off is switched on, the crane lever 8 is moved to the lower position.
Stem 7 moves to the extreme left position, presses on valve 3 and moves it away from seat 4.
Compressed air through the air ducts enters the diaphragm chamber of the switching mechanism.
The diaphragm 6 (see Fig. 1) through the rod 10 with the fork 9 engages the gear 5 of the driven shaft into engagement with the drive gear 3.
When the power take-off is switched off, the crane lever 8 (see Fig. 3) is moved to the upper position.
Stem 7 under the action of spring 5 moves to the extreme right position, breaking away from valve 3.
Through the hole in the stem 10 (see Fig. 1), the chamber of the mechanism for switching on the box communicates with the atmosphere, the air is released from the chamber and, under the action of the spring, the stem with the fork 9 disengages the gear of the driven shaft 14 from engagement with the drive gear 3.
Simultaneously with the release of air into the atmosphere, valve 3 (see Fig. 3) under the action of spring 2 is pressed against seat 4 and separates the inlet and outlet of the valve.
Auxiliary power take-off
Power take-off is made from the input shaft of the transfer case through the movable clutch 2 (Fig. 4) and is designed to drive the winch.
The operation of the auxiliary power take-off is possible with the neutral position of the transfer case gearshift clutch.
A plunger pump is installed in the auxiliary power take-off box to lubricate the bearings of the gears and shafts.
The pump consists of a piston 17 with a discharge valve 18, a safety valve 20 and a casing 22.
The piston with the connecting rod is mounted on the eccentric of shaft 3 and moves forward when it rotates.
In order to prevent excessive pressure with increasing speed, the suction valve is of differential type with a coil spring.
Oil is taken in through a tube 1 connected to the oil bath of the transfer case, and from the pump it enters the gear bearings through channels made in shaft 3 and in the input shaft of the transfer case.
Part of the oil penetrates through the gaps and lubricates the shaft bearings.
To ensure remote activation of the auxiliary power take-off in the cab, to the right of the driver on the lower edge of the instrument panel, a control valve is installed on the bracket.
When the auxiliary power take-off is off, lever 8 (see Fig. 3) is in the upper position, stem 7 is in the right position.
The valve, under the action of its spring, is pressed against the seat 4 and air does not flow through the valve.
When the handle is moved to the lower position, the stem 7 moves to the extreme left position, presses on the valve and moves it away from the seat.
Compressed air enters the switching chamber and turns on the additional power take-off, compressing the spring 8 (see Fig. 4).
When turning off the auxiliary power take-off When necessary, the crane lever is moved to the upper position.
The stem under the action of the spring moves to the extreme forward position, breaking away from the valve.
Through a hole in the rod, the box switching chamber communicates with the atmosphere, the air is released from the chamber, and the spring turns off the box.
Simultaneously with the release of air into the atmosphere, the valve is pressed against the seat under the action of a spring and separates the inlet and outlet of the valve.
The control valve lever is fixed in the off position with a screw mounted on the valve bracket.
With prolonged operation of the auxiliary power take-off, there should be no increased heating of the bearings of the input shaft of the transfer case and the power take-off shaft.
Increased heat indicates a malfunction in the oil pump.
Check the operation of the pump together.
To check pump operation:
- - fully tighten the parking brake lever;
- - set the transfer case gear lever to neutral position;
- - turn off the winch, for which the lever on the right side member of the frame is lowered down;
- — unscrew the plug 19 in the pump housing;
- - start the engine, turn on the auxiliary power take-off and one of the gears in the gearbox;
- —determine the health of the pump by closing the hole for the plug with your finger.
When the pump is working, there is a pulsation of oil in the hole for the plug.
It is forbidden to work with a faulty pump.