To drive the unloading and loading units of vehicles it is necessary to apply additional power sources of power take-off. One or more types of devices transmit the operating force from the engine to the actuators. Here you need a power take-off (PTO).
COM selection
The choice of COM depends on the type of additional equipment and the intended tasks. Optimum operation, quality, simpler installation, lower total cost of the box with installation work are taken into account. Depending on the application, various types of drive mechanisms are connected to the PTO, which transmit force to a working unit that requires power. The technical requirements of the additional equipment determine which unit is most suitable. Since the interaction of the PTO with the power unit and the transmission is crucial, the power take-off must be structurally coordinated with the engine and gearbox.
- The use of increased pressure in the system reduces the size of the pipelines and hydraulic pumps used, which saves space and reduces weight.
- Direct connection of the hydraulic pump to the box reduces the cost of installation.
- A higher gear ratio in the COM makes it possible to use a lower crankshaft speed, which reduces the noise level and reduces fuel consumption.
Dependent type power take-off
Clutch-dependent PTOs are installed on the manual transmission. It is possible to use them only when the engine is idling. They are easy to install and light in weight. A gearbox with a drive from the intermediate shaft of the manual transmission is attached to the rear of the gearbox housing. Speed with power output is determined by engine speed and gear ratio. The clutch-dependent power take-off can be switched on using the pneumatic system at idle speed of the motor. The clutch-dependent power take-off is suitable if the special vehicle is equipped with a manual gearbox and there is no need to take it on the go.
Benefits of a Dependent System
- Dependent COMs weigh less than independent ones.
- There is no overspending of engine power due to the fact that hydraulic oil is not pumped continuously in the system, as it happens during power take-off regardless of clutch.
- The design is simple and robust, the maintenance required is minimal and low installation costs can be achieved. The inability to enable power take-offs when moving the car can be considered an advantage in terms of safety.
Dependent COM models for domestic cars
- KamAZ power take-off mounted to the upper gearbox hatch: MP02, MP03, MP08, MP27, MP55.
- To the right side hatch KP: MP01, MP05, MP07, MP15, MP21, MP22, MP29, MP41, MP50, MP57, MP73, MP74.
- To the left side hatch KP: MP39.
- To the rear end of the gearbox: MP23, MP28, MP47, MP48.
- To the upper hatch of the transfer case: MP24, MP32.
- GAZ power take-off mounted to the right side hatch KP: MP01, MP05, MP07, MP15, MP29, MP41, MP73, MP74, MP82.
For the old model GAZ-53
GAZ-53 became the most massive truck of the USSR. Special equipment was produced on its chassis, in particular fuel trucks. For operation of the pump, a GAZ-53 power take-off is installed on the fuel truck, screwed to the right side hatch of a 4-speed gearbox. The rotation is transmitted to the pump through the universal joint. The inclusion is mechanical. Modification 53b-4202010-08 is connected by splines, and 53b-4202010-09 is connected by flanges. Maximum transmitted power is very small: 9.42 kW.
Independent type power take-off
An independent clutch power take-off can be mounted on a car with a power unit and transmission of any type. You can turn it on when moving and on stationary equipment. Independent KOM is also suitable for its inclusion outside the car. For vehicles requiring continuous access to power take-offs, complete clutch independence is the only solution.
For manual gearbox: the power take-off is driven by the engine flywheel and mounted between the engine and manual transmission. The speed and power are controlled only by the power unit. Power take-offs have an electro-pneumatic / hydraulic switching system made with a friction clutch.
For automatic transmission: KOM is mounted in front from above on a transmission. It is driven by the engine flywheel through a torque converter, which, with the help of a strong drive gear, drives the drive force to the power take-off. Therefore, KOM is not affected by the speed of the converter. The inclusion of power take-off is carried out by electric and hydraulic systems, including while driving.
Grip independent
The box is mounted on the engine. It is included in the operation of the engine camshaft drive. This means that when the motor is running, the KOM works independently, the vehicle is moving or standing. The hydraulic actuator is activated by a safety valve mounted on the hydraulic pump.
Independent COM Models
- KOM KAMAZ mounted to the right side hatch KP: MP121-4202010, MP119-4202010, MP123-4202010.
- To the left side hatch KP: MP114-4202010.
- To the rear end of the gearbox: MP105-4206010.
Installation of MAZ boxes
On the manual transmission , the MAZ power take-off is mounted on the left or right. The location affects the direction of the working shaft, therefore, the placement of the hydraulic pump. Using rubber pads, metal and paronite gaskets, the distance between the gears is adjustable. At the first test run of the installed power box, the torque should be low. The teeth of the gears should grind.