What is a PTO?
Truck PTO / Power Take-Off Gearboxes are used for transferring the required energy for the operation of equipment on commercial vehicles such as dump trucks, cranes, garbage trucks, from the main transmission.
In order to meet the energy required by the equipment via the main transmission, commercial vehicle manufacturers customize some of the gears in their main transmission and make them suitable for PTO installation. Therefore, there is a different PTO output for almost every transmission model and a special PTO model is needed for each output. For this reason, it is very important to determine the right truck PTO / Power Take-Off. Otherwise, both the main transmission gears and the PTO may be damaged and lead to undesirable results.
Split Shaft PTO
If the truck equipment require high power, the power transferred by the gear on the main transmission may not be sufficient. In such cases, a larger PTO type called
Split Shaft PTO (Intermediate Gearbox) is required. Split Shaft PTO’S are mounted on the vehicle chassis and transfers power to the equipment from the truck’s main shaft. We will continue to explain the Split Shaft PTO’S in detail under their own topic on our site.
Note:
- I do not have detailed information about PTO / Power Take-Off selection. How can I find suitable PTO models on your page?
- If you write the code written on the transmission label of your vehicle (ZF S6 35- MO 35 S 5 - ALLISON 1000- EATON 8209- HEMA 542 etc.) in its entirety or 3 digits in the search engine on the top right, the PTO models suitable for your vehicle will be listed.
Which Areas and Vehicles Are PTO / Power Take-Off Used?
- Fire trucks, road cleaning vehicles
- Towing trucks and cranes for carrying heavy materials
- Operating garbage compactor trucks
- Providing suction and spraying for liquid carriers such as tankers
- Use of the dumpers of dump trucks
- Operating drilling equipment such as vacuum trucks, excavation trucks.
- Using farming equipment that requires extra power, such as bale tying machines for tractors
- Concrete mixers, Cement pump Trucks used in the construction industry
PTO / Power Take-Off Duties
Small PTO / Power Take-Off Transmissions
They provide power output through the transmission. These PTOs have many advantages, briefly.
PTO / Power Take-Off Power Output Control: PTO / Power Take-Off Transmission allows the driver to turn the equipment on and off at any time. The PTO control mechanism can be pneumatic, mechanical or vacuum, considering the vehicle features.
PTO / Power Take-Off Speed Control: It enables the most efficient use of vehicle equipment by increasing or decreasing the gear speed received from truck transmission.
PTO / Power Take-Off Torque Control: It evaluates the power received from truck gear and if its needed increase by changing speed/torque ratios.
PTO / Power Take-Off Speed Direction Control: PTOs converts turning direction of main transmission gear to the desirable direction on its outlet.
PTO / Power Take-Off Multiple Output Option: Power Take-Off Units allows multiple PTO outputs so Trucks can run multiple equipment’s on same time.
Creates suitable space for some components. Sometimes, PTO connection places on the truck does not have enough space for pumps or some equipment to be installed, on those cases PTOs can be installed to move PTO outlets on different and suitable positions on the truck.
Power Take-Off Types
Power Take-Offs are units with many varieties, starting from a small gearbox that carries power out of the transmission with only one gear, to more complex versions that increase the number of outlets, speed, torques etc.
Power Take-Offs are divided into many different types and varieties:
-Connection point; small PTOs can be intalled on the main transmission’s the tail or side PTO connection place or on the engine as well as larger PTOs can be installed on the main shafts, engine or between engine and transmission etc.
-Number of gears inside of the PTO; single gear or double gear or multiple gears.
-In terms of engagement method; pneumatic, mechanical, vacuum and electric can be divided into many types.
Power Take-Offs (PTOs) in terms of connection point
From the tail: With this connection point supported by many transmission manufacturers, the PTO outputs are located at the back of the transmission, facing the rear of the vehicle. The installed PTOs receive the power they need through a shaft located in the transmission, change this power and rpm in line with the demands of the equipment and transfer it to the equipment.
Side Connection: This connection point, preferred by many Far Eastern vehicle manufacturers, is located on the sides of the transmission and provides its power through a special gear located in the transmission.
From the Engine: This type of PTO works by connecting to the vehicle engine. Since the vehicle engine is always running, engine PTOs cannot be stopped unless the vehicle engine is stopped. In order to use these outputs efficiently and control the output, manufacturers use clutch linings, hydraulic pumps and they can create solutions using valve systems.
Power Take-Off Gears (PTOs) According to Gear Numbers
Single gear:
Single gear PTOs also have lower output speed compared to more complicated versions. Tale connection versions have transfer ratio of 1:1 and side connection versions have lower speed due to single transfer gears.
Double Gear:
Double gear PTOs provide faster speed. In some cases, truck PTO outlet gives insufficient speed to run equipment on the truck. In these cases, double gear PTOs can use both of their gears to increase speed to reach desirable level to run equipment.
Power Take-Off Gears (PTOs) in Terms of Control Systems
Pneumatic Controlled: Most common and efficient control system. Many modern trucks uses high pressure air power to engage and disengage the PTOs. Pneumatic control is the most common and efficient way to control PTOs. User should check the air pressure on the truck to be sure system works without any problem.
Mechanical Controlled: This control system, which is generally used in medium and small-sized commercial vehicles, is used if there is no pneumatic air system in the vehicle. Power is provided by engaging 2 gears to each other via a metal cable similar to a brake cable with the help of a mechanical arm and transferring the transmission power to the equipment.
Vacuum Controlled: In vehicles without a pneumatic air system, this system was offered as a solution to the demands due to reasons such as the mechanical cable not being extended enough. In this PTO model, the power required for the gears to engage with each other is obtained from the vacuum system controlling the vehicle brake. The vacuum received with a T connector is connected to the PTO air tube, ensures that the gears engage with each other. The main difference here from the pneumatic system is that the air tube is pushed in the pneumatic system and pulled in the vacuum system. Since the connection of the vacuum system of vacuum-controlled PTOs requires intervention in the vehicle brake system, it must be done by professionals.
Electrical System PTOs: These types of PTOs are engaged with an electromagnet. This system, which cannot be used efficiently due to malfunctions in the electronic system, is not very popular due to its price-performance ratio.