Power take-offs or air power take-offs ( PTO ) is any of several methods of taking power from a power source, such as a running engine and transmitting it to an application such as an attached implement or a separate machine to achieve several turns and power to be able to develop our application.
The PTO element transforms the mechanical power from the gearbox into hydraulic power with the help of the pump that is mounted in conjunction with the PTO.
Airpower take-offs can be mounted on a truck, a tractor, an agricultural sprayer, a brush cutter, a fertilizer spreader, a power tiller, a crane, and even on a pickup truck. There are many applications where the idea is to adapt a hydraulic pump to a heat engine, as long as the gearbox allows it. And if it does not, they are adapted with a Cardan shaft support and transmission.
More commonly, you see a splined driveshaft installed on a tractor or truck that allows implements with coupling attachments to be driven directly by the engine.
semi-permanently mounted PTOs can also be found on industrial and marine engines. These applications typically used a drive shaft and bolted joint to transmit power to a secondary implement or attachment. In the case of a marine application, such posts can be used to drive fire pumps.
When ordering a PTO, it is crucial to know the model and make of the gearbox. Most commercial vehicles have one or more registers in the gearbox for a PTO to be installed. Each window may offer a different gear ratio. Depending on the position of the register, we will have:
- Sides: The window for fixing the PTO is on one of the sides of the gearbox, right or left, always looking at the gearbox from the rear of the vehicle.
- Rear: The fixing window is located at the rear of the gearbox.
- Lower (or Ventral): The fastening window is located in the gearbox’s lower part or “belly.”
Depending on the type of application, the PTO can have different outlets. The most common are:
- Compact output for pumps. (ISO 4 bore, UNI 3 bore, SAE A, SAE B, SAE C).
- Plate output connects to a transmission (SAE 1100, SAE 1300, SAE 1400, DIN 90, DIN 100, DIN 120, etc.).
To calculate the power consumption, it is necessary to know our application’s pressure and flow rate. Then, depending on the number of pinions that the power take-off has, we can choose the direction of rotation.
The power take-off must be purchased separately, and care must be taken to match the physical surface of the transmission with compatible power take-off. A power take-off is used when superstructures, such as hydraulic pumps or other accessories need to be executed. The PTO is mounted on the main transmission of the truck. The mounting can be rear, left or right, or even on the underside of the information. The units are used on dump trucks and Ram-type vehicles, hook loaders, flatbed vehicles, and fuel tanks. In addition, some heavy-duty units are used on fire trucks, combination cleanup trucks, and concrete pumping trucks. PTOs can be single or dual output. Depending on the hydraulic pump housing, the outlets can be ISO or UNI type. The PTO is engaged/disengaged using the primary transmission clutch and a remote-control mechanism operating on the PTO. Usually, an air valve is used to activate the PTO, but there are also the options of a mechanical, electric, or hydraulic mechanism.