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 housingClutch Dependent:3. Driven by the transmissionTransmission dependent4. Driven by the Transfer Box5. Split-Shaft Box55
2 POWER TAKE OFF APPLICATIONS 1. Engine mounted2. Integrated in the clutch bell housing3. Driven by the transmission4. Driven by the Transfer Box5. Split-Shaft Box
3 TRANSMISSION DRIVEN PTO’s Suitable for most applicationsEasy, low-cost installationRetrofit always possibleSide Mounted PTOThe PTO is driven by one gearoff the layshaft.Suitable for regular or heavy dutyand intermittent operation.Rear Mounted PTOThe PTO is direct drivenby the splines at the end of thetransmission’s layshaft or, alternatively, of anextension or auxiliary shaft.Suitable for heavy duty, continuous operation.
4 SELECTING THE PTOThe 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 ModelPTO mounting locationPTO rotationGear positionPTO speedPTO output torquePart numbers of stud kits, spacers, adapters
6 TRANSMISSION MAKE AND MODEL 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 nameTransmission model1st gear ratio.shown hereunder refers to an EATON transmission)(The example shown hereunder refers to an EATON transmission)EATON spec numberCustomer spec number/descriptionModel numberSerial numberDate of manufacturing
7 PTO MOUNTING SIDEBefore 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 beused simultaneously. In this case themaximum allowed power output offthe transmission should not be exceeded.Our technical department should be contactedwhen several PTO’s are operatedsimultaneously1 SUP Upper2 INF Bottom3 POS Rear4 DX Right Hand5 SIN Left Hand6 ANT Front
9 PTO ROTATION It is a key factor for the correct selection of pumps or othermechanical devices that have to berun with only one rotation sense.The rotation you find in thecatalogue refers to the rear output,i.e. with the PTO output shaftpointing toward the rear of the truck.Therotation only refers to the frontoutput if for some technical reasonsthe PTO is not provided with the rearoutput.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 oppositerotation to that of the PTO.Some PTO Manufacturers refer the PTO rotation to the rotation of the engine crankshaft. In this case “engine” rotationcoincides with anticlockwise PTO rotation.SX = Left handAnticlockwiseDX = Right handClockwise
10 GEAR POSITIONPIt 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 = FORWARDC = MIDDLEP = REARWARDFront of vehicle
11 PTO SPEEDPIt 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 TORQUEPThe 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 CALCULATIONSAs 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 pumpsblowers, compressors, generators, etc.
14 DRIVING HYDRAULIC PUMPS The FlowIn 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 CapacityThe 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 SpeedThe 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.
15 DRIVING HYDRAULIC PUMPS The Absorbed TorqueThe 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:
16 DRIVING COMPRESSORS, GENERATORS etc. 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 expectedPTO operating life in the case of different operating conditions.P Required PTO output power in kWN PTO output speed in rpmM required torque = ( P / n )Mn nominal torque, see PTO catalogueKt 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:= = kWThe following diagram shows theallowed duration for continuousoperation, depending on theenvironment temperature:0° = 44’ (minutes) max20° = 24’ (minutes) max40° = 15’ (minutes) maxN (Nm) x n (rpm)9552P (kW) =300 (Nm) x 1850 (rpm)ßAbsorbed Power (kW)Environment Temperature (C°)Continuous Working Time (minutes)