Presentation is loading. Please wait.

Presentation is loading. Please wait.

POWER TAKE OFF’s 5 5 Engine Dependent: 1. Engine mounted

Similar presentations

Presentation on theme: "POWER TAKE OFF’s 5 5 Engine Dependent: 1. Engine mounted"— Presentation transcript:

1 POWER TAKE OFF’s 5 5 Engine Dependent: 1. Engine mounted
2. Integrated in the clutch bell housing Clutch Dependent: 3. Driven by the transmission Transmission dependent 4. Driven by the Transfer Box 5. Split-Shaft Box 5 5

1. Engine mounted 2. Integrated in the clutch bell housing 3. Driven by the transmission 4. Driven by the Transfer Box 5. Split-Shaft Box

Suitable for most applications Easy, low-cost installation Retrofit always possible Side Mounted PTO The PTO is driven by one gear off the layshaft. Suitable for regular or heavy duty and intermittent operation. Rear Mounted PTO The PTO is direct driven by the splines at the end of the transmission’s layshaft or, alternatively, of an extension or auxiliary shaft. Suitable for heavy duty, continuous operation.

4 SELECTING THE PTO The catalogue includes all necessary information for the correct Power Take Off selection for each different application. Before consulting the catalogue the following preliminary information should be collected: What is the make and model number of your transmission? What type of equipment will your PTO be driving? Your driven equipment requires what horsepower, what rpm and what rotation? The information in the PTO Selection Catalogue include: Transmission Make and Model PTO mounting location PTO rotation Gear position PTO speed PTO output torque Part numbers of stud kits, spacers, adapters


Successful Power Take Off selection requires correct transmission identification. Transmissions are identified by the manufacturer’s tag located in various positions, depending on the manufacturer and the specific transmission. The tag usually shows the following data: Manufacturer’s name Transmission model 1st gear ratio.shown hereunder refers to an EATON transmission) ( The example shown hereunder refers to an EATON transmission) EATON spec number Customer spec number/description Model number Serial number Date of manufacturing

7 PTO MOUNTING SIDE Before selecting the PTO location the main technical specifications (speed and torque) of the available PTO’s in the different locations have to be evaluated. In the case more PTO apertures are available the one offering the most convenient installation should be preferred. More than one PTO apertures may be used simultaneously. In this case the maximum allowed power output off the transmission should not be exceeded. Our technical department should be contacted when several PTO’s are operated simultaneously 1 SUP Upper 2 INF Bottom 3 POS Rear 4 DX Right Hand 5 SIN Left Hand 6 ANT Front


9 PTO ROTATION It is a key factor for the correct
selection of pumps or other mechanical devices that have to be run with only one rotation sense. The rotation you find in the catalogue refers to the rear output, i.e. with the PTO output shaft pointing toward the rear of the truck. The rotation only refers to the front output if for some technical reasons the PTO is not provided with the rear output. A special remark is made in this case. Attention! The PTO rotation is defined by looking at the PTO output face. As a consequence the pump must have opposite rotation to that of the PTO. Some PTO Manufacturers refer the PTO rotation to the rotation of the engine crankshaft. In this case “engine” rotation coincides with anticlockwise PTO rotation. SX = Left hand Anticlockwise DX = Right hand Clockwise

10 GEAR POSITION P It is considered to be a useful detail for a fist sight check of the transmission gear that is supposed to drive the PTO gear. The catalogue indicates the location of the gear related to the vertical centreline of the PTO opening. A = FORWARD C = MIDDLE P = REARWARD Front of vehicle

11 PTO SPEED P It is the rpm that is actually available for driving the installation and it is the parameter that can affect the performance of the whole system. All the speeds given in the catalogue are calculated considering a nominal engine speed of 1000 rpm. Some gearboxes can drive the PTO with several different speed ratios, depending on the selected gear. The catalogue lists all available ratios to the PTO.

12 PTO OUTPUT TORQUE P The available torque at the PTO output depends mainly on the constructional parameters of the PTO. The torque of the selected PTO should match with the specifications of the driven equipment. The indicated torque values are Nm and are the maximum available for each output. Important! Always make sure that the absorbed torque off the gearbox is lower than the maximum allowed by the gearbox itself. Please contact our technical department for further information.

13 PTO CALCULATIONS As previously shown, speed and output torque are the main criteria for proper PTO selection. These factors depend on the technical specifications of the driven equipment. Some typical PTO driven devices are: hydraulic pumps blowers, compressors, generators, etc.

The Flow In installations operated by single acting or double acting cylinders the required flow Q in litres per minute is: where V is the required oil volume in litres to accomplish a complete tipping (or any other) operation and t in seconds is the time to complete the same action. The Pump Capacity The required pump capacity C in cc/rev is given by the formula: where Q is the required flow in litres per minute and n in rpm is the PTO output speed. The Pump Speed The speed n in rpm of the PTO driven pump is: where n1 is the PTO output speed at 1000 engine rpm (this value is found in the catalogue) and n2 the engine rpm during the PTO operation.

The Absorbed Torque The absorbed torque by the system is calculated using the following formula: where C is the pump capacity in cc/rev, P the pressure in bar (use the setting pressure of the relief valve of the system) and M is the absorbed torque by the pump in Nm. M must never exceed the value of the PTO torque reported in the catalogue. Above formula takes into account an average mechanical efficiency of the pump. Please notice that:

Use the following formula to calculate the required torque for driving compressors, generators or any other equipment, when the absorbed horsepower and the operating speed are given: where n is the equipment speed in rpm and N is the absorbed power in kW. The resulting torque M absorbed by the equipment must not exceed the value indicated in the catalogue for the selected PTO. Please notice that: For special applications, or if you require further instructions or information please call or write our Technical Assistance.

17 PTO OPERATING LIFE PTO’s are designed for a calculated operating
life of 500 working hours at 1000 rpm. The following diagram indicates the expected PTO operating life in the case of different operating conditions. P Required PTO output power in kW N PTO output speed in rpm M required torque = ( P / n ) Mn nominal torque, see PTO catalogue Kt Load coefficient = 100 ( M / Mn ) t PTO expected operating life in hours

18 CONTINUOUS OPERATION ß Absorbed Power (kW)
The duration of continuous, high horsepower PTO operation is restricted by the risk of overheating the Transmission – PTO assembly. Example: If the required torque N is 300 Nm and the PTO output speed is 1850 rpm, then the power absorbed by the installation is: = = kW The following diagram shows the allowed duration for continuous operation, depending on the environment temperature: 0° = 44’ (minutes) max 20° = 24’ (minutes) max 40° = 15’ (minutes) max N (Nm) x n (rpm) 9552 P (kW) = 300 (Nm) x 1850 (rpm) ß Absorbed Power (kW) Environment Temperature (C°) Continuous Working Time (minutes)


DIN Flanges SAE (Spicer) Flanges

Download ppt "POWER TAKE OFF’s 5 5 Engine Dependent: 1. Engine mounted"

Similar presentations

Ads by Google