Man trucks guidelines for power take offs

MANTED®

Guidelinesto fitting bodies

Power take-offsPower take-offs (PDF, 0.650 KB, 09/2007)(_pdf/powertakeoffs_gb.pdf)

na_zf_tab (PDF, 1.700 KB, 03/2009)(_pdf/nebenabtriebe/na_zf_tab_gb.pdf)na_eaton_tab (PDF, 0.250 KB, 09/2007)(_pdf/nebenabtriebe/na_eaton_tab_gb.pdf)

PUBLISHER MAN Nutzfahrzeuge AG ESC Department

Engineering Services Consultation (formerly TDB)

Dachauer Str. 667 D - 80995 Munich

E-Mail: [email protected] Fax: + 49 (0) 89 1580 4264

(#Anchor-46841)7. Power take-offs(#Anchor-26094)

(#Anchor-46841) 7.1. Fundamentals (#Anchor-55433)

(#Anchor-46841)7.1.1 Calculating power andtorque(#Anchor-38720)

(#Anchor-46841)7.1.2 Drive shaft connection topower take-off(#Anchor-55033)

(#Anchor-46841)7.2. Regulating enginespeed(#Anchor-4669)

(#Anchor-46841)7.2.1 Regulating engine speedwith Tempomat(#Anchor-23653)

(#Anchor-46841)7.3.1.3 Camshaft drive, powertake-off at the flywheel(#Anchor-46550)

(#Anchor-46841)7.3.1.4 Power take-off ontransfer case(#Anchor-6217)

(#Anchor-46841)7.3.2 Power take-off ongearbox(#Anchor-25061)

(#Anchor-46841)7.3.2.1 Differentiation(#Anchor-43201)

(#Anchor-46841)7.3.2.2 Clutch-dependent powertake-offs(#Anchor-59478)

(#Anchor-46841)7.3.2.3 Engine-dependent

MANTED: Guidelines-Power take-offs http://www.manted.de/manted/aufbaurichtlinien/gb_powertakeoffs.html

1 of 16 12/16/2012 3:42 PM

(#Anchor-46841)7.2.2 Engine speed regulation viathe ZDR interface(#Anchor-44997)

(#Anchor-46841)7.2.3 Starting and stopping theengine from outside the cab(#Anchor-62419)

(#Anchor-46841)7.2.4 Blocking thegearshift(#Anchor-13617)

(#Anchor-46841)7.3. Technical description ofpower take-offs(#Anchor-32804)

(#Anchor-46841)7.3.1 MAN powertake-offs(#Anchor-47867)

(#Anchor-46841)7.3.1.1 V-belt pulley(#Anchor-1253)

(#Anchor-46841)7.3.1.2 Power take-off at aircompressor(#Anchor-17347)

power take-offs(#Anchor-15567)

(#Anchor-46841)7.3.2.4 Power take-offs ongearboxes with converter lock-up clutch(#Anchor-42114)

(WSK)(#Anchor-42114)

(#Anchor-46841)7.3.2.5 Power take-offs on ZFHP automatic transmissions(#Anchor-60207)

(#Anchor-46841)7.3.2.6 Power take-offs andIntarder(#Anchor-25624)

(#Anchor-46841)7.3.2.7 Power take-offs for ZFtransmissions(#Anchor-43359)

(#Anchor-46841)7.3.2.8 Power take-offs forEATON transmissions(#Anchor-29635)

7. Power take-offs

7.1. Fundamentals

Power take-offs can be installed at the following points, in some cases at several of them at once:

• On the engine - at the front end of the engine - on the front end of the crankshaft, using a twin-groove V-belt pulley - as a pump directly attached to the air compressor - at the rear end of the engine (e.g. camshaft drive, power take-off at the flywheel)• On the gearbox• On the transfer case.

When choosing a power take-off, the following points must be considered:

• Permissible torques• Direction of rotation• Jolt factors• Operating life• Critical speed of rotation• Maximum length of drive shaft• Angle at drive shaft joints• Reduction ratio• Cooling (avoidance of trapped heat at the power take-off)• Installation and accessibility• Means of attachment (of pump)• Instructions issued by power take-off manufacturer• Instructions issued by pump manufacturer• Instructions issued by drive shaft manufacturer.

Power take-off manufacturers have issued their own publications containing detailed information on:

• Correct choice of power take-off• Correct operation• Avoidance of vibration or how to eliminate it.

The power take-off’s maximum permitted torque can be fully utilised only if operation is entirely free from jolts


2 of 16 12/16/2012 3:42 PM

and vibration. This is seldom possible, and therefore jolt factors must be taken into consideration whenchoosing the power take-off. Table 1 shows the relationship between torque and jolt factor for several typicalapplications.

The dimensioning of the power take-off must allow for the maximum torque that will be encountered, includingthe jolt factor.

Table 1: Torques and jolt factors for power take-offs

Power take-offs must be protected against overheating; if necessary the manufacturer of the superstructuremust install a fan. Heat must not be trapped; inadequate heat dissipation will cause damage.

Notes on transmission oil temperature:

The transmission and transfer box oil temperature may not exceed 110°C during operation. Peak temperaturesof max. 130°C are still permissible for a maximum of 30 minutes. If a check reveals that the oil temperaturereaches higher values, then some form of external cooling (e.g. a fan) must be provided.

If parts of the engine enclosure have to be removed in order to install power take-offs, they must be replacedby suitable items provided by the installing company, to ensure that excessive noise is not emitted. Please noteand comply with the instructions in the "Engine modifications" section of the "Modifying the chassis" Chapter (inthe booklets relevant to the range).

Power take-offs are not designed to accept radial bearing loads imposed by chains or V-belt drives. For thisreason, chain sprockets or V-belt pulleys are not to be attached directly to the power take-off. Leading driveshaft manufacturers issue documentation on the anticipated reduction in operating life and higher axial andradial forces at the bearings. This information must be taken into account when determining the drive rating; areduction in transmitted power is to be expected.

If the equipment to be driven could overload the power take-off, some form of overload protection must beinstalled. This also applies if only occasional peak torques beyond the permitted limit occur. As is customary inmechanical engineering, all directions of rotation are quoted "looking at the shaft journal”, that is to say at theoutput point.

For TG vehicles MAN workshops can parameterise the production standard interface and provide cabling forspeed and torque limiters.

The following are not permitted:

• Engine speeds < 800/min with the power take-off engaged and under load• Even-numbered drive or reduction ratios such as 1:1, 1:2 etc., since vibration could occur as a resultof resonance.

7.1.1 Calculating power and torque

Before the correct power take-off can be selected, the following details of the equipment it is to drive must beavailable:


3 of 16 12/16/2012 3:42 PM

• Power requirement, torque• Direction of rotation• Operating time• Speed of rotation• Jolt factors.

The torque can be calculated using the formulae quoted in chapter 9, "Calculations" (in the booklets relevant tothe range), where examples are also provided.

7.1.2 Drive shaft connection to power take-off

For the drive shaft connection, the principles laid down in the "Drive shafts” section of the "Modifying thechassis" Chapter (in the booklets relevant to the range) are to be applied. For the drive shaft joint angles, thefollowing conditions must be complied with:

• Joint anglel ≤ 7°, a tolerance of +1° is permitted• Absolute difference in angle of ≤ 1°, between the two joint angles of a shaft; 0° should be aimed for.

The stated values apply to both single-plane and three-dimensional drive shaft systems. In the case of three-dimensional drive shaft systems, the resultantthree-dimensional joint angle must be taken into account. Exceptions to the stated values must be expresslyapproved by the ESC Department at MAN (For address see “Publisher” above).

Drive shafts in areas in which people move, stand or work must be covered or shielded.

(#Anchor-16041)

7.2. Regulating engine speed

Whether the vehicle is being driven or used to operate power take-offs, the power required from the engine isnot normally constant. The fluctuation in power requirement at a constant speed of rotation has to be equalisedby varying the amount of injected fuel.

At a constant speed of rotation, the following therefore applies:

• Lower power requirement – less fuel injected• Higher power requirement – more fuel injected.

Depending on the vehicle’s body and its intended purpose, the power take-off and therefore the engine arerequired to run either at a minimum, a constant or a maximum speed. In most cases more than one of theserequirements has to be fulfilled. For engines with EDC (Electronic Diesel Control), the body manufacturer willmodify the ZDR (Intermediate Speed Control) interface.The set speeds are maintained at a constant level even when the load varies; the accuracy of this system isalways greater than that of a mechanical system.

7.2.1 Regulating engine speed with Tempomat

MAN trucks and tractor units are fitted with a cruise control lever to regulate the vehicle’s speed. At speeds ≤20km/h this allows the engine speed to be regulated even without intervention in the ZDR interface. Thememory button (2nd on the left) allows a constant speed to be set, with the + and – buttons a working speedcan be set that is between an upper and lower limit and this remains constant until the off button in pressed(2nd on the right) or another switch-off condition(e.g. operating the brakes) occurs. The speed value can be permanently saved by pressing the memory button(depress the 2nd button on the left for 2 seconds)so that, even after the engine has been turned off and/or the vehicle has been driven a short distance, it can becalled-up again by briefly pressing the memory button (2nd on the left).


4 of 16 12/16/2012 3:42 PM

Fig. 1: Layout and functions of cruise control lever ESC-162

7.2.2 Engine speed regulation via the ZDR interface

The EDC control unit can be programmed to obtain suitable engine speed settings when power take-offs are tobe used.

The following can be set:

• Speeds (i.e. reduced top speed when power take-off is in use)• Intermediate speeds• Speed limits if intermediate speed control is required (e.g. for protection of the unit)• Regulating behaviour and characteristic• Switching preconditions.

The body-mounted equipment control system intervenes (e.g. by a switching signal to run up to apredetermined intermediate speed) and its operating status is recorded (e.g. parking brake, gearbox in neutral,power take-off switch setting) by way of the ZDR interface.In order to use these options the following data are required:

• ZDR interface (for the 2000 ranges L2000, M2000 and F/E2000)• Interface for intermediate speed control at the vehicle management computer ZDR at FFR (series standardfor all vehicles in the TG ranges)• KSM - Customer-specific control module (optional) (series standard for all vehicles in the TG ranges).

A detailed description of the FFR and KSM interfaces with examples of use and current documentation on thehard and software can be found in the “TG Interfaces” booklet.

Industry-specific parameters can already be programmed at the factory if the desired values are provided ingood time to the MAN salesperson by the body manufacturer. Amendments can be made at a later date usingthe MAN-cats® diagnosis system.There is a charge for this service.

7.2.3 Starting and stopping the engine from outside the cab

Certain body-side equipment requires that the vehicle’s engine can be started or stopped from outside the cab.MAN offers a „preparation for engine start and stop device at the end of the frame“ regardless of how theintermediate engine speeds are controlled (see above).

The following always applies when this package is fitted:

• Gearbox neutral selection switch, so that the engine can be started only if neutral has been selected• Parking brake signal recognition, so that the engine can be started only if the parking brake has beenapplied• Start inhibit relay; if the engine is already running it cannot be started again.

Retrofitting the interface is possible but requires detailed knowledge of electrics/electronics and the MAN


5 of 16 12/16/2012 3:42 PM

on-board network. We therefore advise ordering it from the factory. The start/stop device is connected as shownin Fig. 2 (2000 range) or as in the interface description in the “TG interfaces” booklet (TG range).The connecting cable is rolled up at the end of the chassis.If the vehicle must not be moved during power take-off operation, we additionally advise the fitting of a gearshift inhibitor (see the next section).

Fig. 2: Connection to the preparation for start/stop device ESC-163

7.2.4 Blocking the gearshift

On certain vehicles/types of body it is necessary to ensure that the power take-off can be engaged only if thevehicle is not in gear. By inhibiting the gear shift, the opposite effect is also achieved, namely that a gearcannot be selected if the power take-off is already operating. The MAN gear shift inhibitor has the effect of an„exclusive OR switch“, i.e. either a gear or the power take-off can be selected but not both at the same time.

We advise the fitting of a gear shift inhibitor if engine speed regulation and/or an engine start outside the cabare to be provided and the vehicle cannot or must not be moved.

7.3. Technical description of power take-offs

7.3.1 MAN power take-offs

MAN manufactures the following power take-offs itself:

• V-belt pulley, engine-dependent; for description see Section 7.3.1.1• Power take-off at the twin-cylinder air compressor, engine-dependent; see Section 7.3.1.2• Output from camshaft, engine-dependent; for description see Section 7.3.1.3• Power take-off on transfer case; either engine-, gearbox- or distance-dependent can be selected; fordescription see Section 7.3.1.4.

7.3.1.1 V-belt pulley

It is possible to fit a V-belt pulley with an effective diameter dw = Ø 242mm with two grooves at the front end ofthe crankshaft on the D08 engine. This V-belt pulley is installed at the factory in connection with a hydraulicpump (see Table 2), on the right hand side in the direction of travel. In addition, a poly-V belt pulley with adiamet dw = Ø 224,8 mm is fitted to the crankshaft on vehicles fitted with air conditioning to drive the airconditioning compressor.

L2000/ M2000: If air conditioning is fitted this output point is occupied by the air conditioning compressor.TGL/TGM: Aircon and power take-off can be combined. Narrow V-belts DIN 7753 (air conditioning compressor)or international ISO 2790 are to be used as the transmission element. When calculating the power rating,proceed according to DIN 7753 Part 2 or as per information provided by the belt manufacturer.

MAN can supply ex-factory various sub-assemblies that are driven by V-belts or poly V-belts, in particularhydraulic pumps.Hydraulic pumps fitted at the factory are mounted on the crankcase bracket. Other units may also be mountedhere if the unit does not weigh more than 11kg.


6 of 16 12/16/2012 3:42 PM

(#Anchor-16041)

7.3.1.2 Power take-off at air compressor

It is possible to attach hydraulic pumps directly to the flange at front end of the air compressor on D28 engines;see Fig. 3 and 4.

Fig. 3: Output point at front of two-cylinder air compressor on D28 Euro 3 engine ESC-164Fig. 4: Examples of hydraulic pumps at front of two-cylinder air compressor on D28 Euro 3 engine ESC-165

For this power take-off it is essential that the engine is equipped with a two-cylinder air compressor; comparedto output via V-belt it has the following advantages:

• Cab air-conditioning and power take-off on the engine for mechanical components on the body are bothpossible at the same time.• Direct engine-dependent drive from the air compressor; V-belt drive with rating selected by the bodymanufacturer is not needed.

MAN can fit various hydraulic pumps, for example those stated in Table 2, ex-factory to the front end of the aircompressor. Information on the sales programme can be obtained from the national subsidiary; drawings areavailable from ESC department. (For address see “Publisher” above).

Table 2: Technical data: Hydraulic pumps for mounting on two-cylinder air compressor, transmission and endof crankshaft

Engine type Speed factor Hydraulic pumpVolume per revolution incm2

Pressure during continuousoperation in bar

D08 1,175 Hydraulic pump 19 19016 230

Double hydraulicpump

14 + 5,5 20016 + 8 250

D28 1,15 Hydraulic pump 32 210Double hydraulicpump 25 + 11 210

D20 1,194 Hydraulic pump 32 25022,5 23011 280

Double hydraulicpump

22,5 + 32 23011 + 22,5 230

7.3.1.3 Camshaft drive, power take-off at the flywheel

The output point is located at the end of the engine but is not in fact on the camshaft. These power take-offs


7 of 16 12/16/2012 3:42 PM

are permanently engaged. Camshaft drive is available for engines with the D28 designation (i.e. for F2000,E2000, TGA). Power take-off at the flywheel is available for engines with the D20/26 designation (TGA,TGS/TGX vehicle range) and 6 cylinder D08 engines (TGA and TGM vehicle range).

Power take-off data for camshaft drive with the D28 engine:

Flange Ø 100 6-hole 8mm Speedl = 1,075 x engine speed

• Direction of rotation as for the engine, counter-clockwise looking in the direction of travel• Engine speed ≥ 800 rpm with load on camshaft output• Maximum nominal torque ≤ 600Nm for continuous operation• Maximum peak torque ≤ 720Nm for short-term operation (defined as ≤ 1% of the full operating period).

With output in a radial direction (e.g. V-belt, chain) the following also apply:

• Permitted bending moment Mbzul ≤ 250Nm• Permitted radial force FR ≤ 2.500N.

Fig. 5: Camshaft drive with the D28 engine ESC-828

Power take-off data for power take-off at the flywheel with the D20 and D26 engines::

Flange Ø100 6-hole 8mm Speedl = 1,233 x engine speed

• Direction of rotation as for the engine, counter-clockwise looking in the direction of travel• Engine speedl ≥ 800 rpm with load on camshaft output• Maximum nominal torque ≤ 650Nm for continuous operation• Maximum peak torque ≤ 720Nm for short-term operation (defined as ≤ 1% of the full operating period).

With output in a radial direction (e.g. V-belt, chain) the following also apply:

• Permitted bending moment Mbzul ≤ 250Nm• Permitted radial force FR ≤ 2.500N.

Fig. 6: Power take-off at the flywheel for the D20 engine ESC-820


8 of 16 12/16/2012 3:42 PM

Power take-off data for power take-off at the flywheel with the 6 cylinder D08 engine:

Flange Ø100 6-hole 8mm Speed = 1,195 x engine speed

• Direction of rotation as for the engine, counter-clockwise looking in the direction of travel• Maximum nominal torque ≤ 350Nm for continuous operation.

• Maximum peak torque ≤ 720Nm for short-term operation (defined as ≤ 1% of the full operating period).

Fig. 7: Power take-off data for power take-off at the flywheel with the 6 cylinder D08 ESC-830

Flange Ø 100 6-hole 8mm Speed = 1,195 x engine speed

• Direction of rotation as for the engine, counter-clockwise looking in the direction of travel• Maximum nominal torque ≤ 350Nm for continuous operation.

The maximum permitted drive shaft deflection angle of 7° (see also the section „Drive shaft connection to powertake-off“) and the need to avoid peak loads and vibration should be particularly noted.

Resilient double-flange coupling 81.38500.6035 is available as an option. This is mandatory for equipment witha high jolt factor Mmax / Mmin ≥ 2 (see also Table 1), and is recommended for all other bodies to avoid noise andresonance and to ensure overload protection. The double-flange coupling is fitted between the power take-offand the equipment to be driven (equipment-side).

7.3.1.4 Power take-off on transfer case

On the two-gear version of the transfer case (in each case with driver-engaged off-road ratio) a flange for apower take-off can be installed in addition to the output points for the front and rear axles. This output point isat the rear of the transfer case (see Fig. 5).

The power take-off can be engaged and disengaged independently of gear changes or the additional off-roadratio in the transfer case.

The transfer-case power take-off can also be used when the vehicle is stationary. For this, a gear must beselected and the transfer case placed in neutral.

Regardless of the nature of power take-off operation, the following apply:

• The power take-off rotates only when a gear has been selected.• The direction of power take-off rotation depends on which gear has been selected: → forward gear = counter-clockwise rotation → reverse gear = clockwise rotation (in both cases looking in the direction of travel).

Table 3: Technical data for power take-off on transfer case


9 of 16 12/16/2012 3:42 PM

Transfer case RangeTransfer case

installation drawing

Ratio

On-road

Ratio

Off-road

Permissibletorqueat

power take-off[Nm]

Flange Ø [mm]

G1000-2L2000,

M2000L/M 81.37000.8132 1,061 1,607≤ 8000

Ø 155

4 hole

M12x1, 5x45

G1700-2

G173

F2000, E2000

/ TGA

81.37000.8118

81.37000.8170 1,007 1,652

G2500-2

G253

F2000, E2000

/ TGA

81.37000.8124

81.37000.8170 0,981 1,583

Fig. 8: Power take-off on transfer case ESC-166

The MAN power take-off on the transfer case is:

• Gearbox-dependent• Distance-dependent• Transfer-case dependent.

1. Gearbox-dependent operation:

If the power take-off on the transfer case is to be used with the vehicle stationary, the transfer case must be setto neutral.The required power take-off drive ratio with the vehicle stationary is obtained by selecting any gear at the maingearbox.The power take-off ratio with the vehicle stationary is thus equivalent to the corresponding main gearbox ratio.

2. Distance-dependent operation

Installed equipment that is required to perform a given number of rotations for a given road distance must bedriven by a distance-dependent power take-off. Since the transfer case output is governed by both the on-roadand off-road ratio groups, two different ratios can be selected for distance-dependent operation.Distance-dependent operation of the power take-off ratio depends on:

• The transfer case ratio• The final drive ratio at the driven axle(s) and• The tyre size.

As a parameter for the ratio the number of power take-off revolutions per metre of distance covered can bequoted, or alternatively the reciprocal value, that is to say the distance covered in metres per revolution of the


10 of 16 12/16/2012 3:42 PM

power take-off. In the distance-dependent mode, the main gearbox ratio or the engine speed are not thefundamental factors governing the power take-off ratio.

3. Transfer case-dependent operation:

Transfer case-dependent operation takes place in a similar manner to distance-dependent operation. Thedifference lies in the fact that either the on-road or the off-road group can be selected when the transfer case isengaged, so that two different power take-off ratios are possible.

Please refer to Chapter 9, „Calculations“, in the booklets relevant to the range for an example of how tocalculate the ratio of the transfer-case power take-off.

(#Anchor-16041)

7.3.2 Power take-off on gearbox

7.3.2.1 Differentiation

Power take-offs can be distinguished according to the following factors:

• Operating period

Table 4: Power take-offs and operating periods

Operating periodShort-period operation < 60minContinuous operation ≥ 60min

• Power flow dependencies - engine-dependent power take-off - clutch-dependent power take-off.

Table 5: Power take-offs – relationship between operating period and power flow with relevant power take-offdesignation

Engine-dependent Clutch-dependent

ZF ZF EATON

Short-period operation <60min

N../4b, c

N36/5b, c

NM AS/10b, c

Continuous operation ≥60min NMV

N../1b, c

N../10b, c

NM AS/10b, c with fan or cooling set

81Z2

2266

290x (+500x)

7.3.2.2 Clutch-dependent power take-offs

By way of the main shaft (also the gearbox input shaft) one pair of gears is driven when the engine is runningand the clutch is engaged. This causes the countershaft to rotate as well. When the clutch is operated, internal


11 of 16 12/16/2012 3:42 PM

resistance to rotation in the gear train causes the countershaft to come to a standstill. In this operatingcondition the power take-off can be engaged.

The drive ratio between engine and gearbox is determined by the ratio of the gear pair between the main shaftand the countershaft. If identical power take-offs are fitted to different gearboxes, their speed factors (f) will varyaccording to the basic gearbox ratio.

Fig. 9: Example: Schematic gearbox diagram of clutch-dependent power take-off ESC-070

Engagement:

The power take-off is engaged pneumatically via a switching valve and a pneumatic cylinder, located inside thePTO housing, that is pressurised on one side.

Operation:

It is possible to operate the power take-off with the vehicle both at a standstill and when it is in motion. Turningthe power take-off on and off must be done with the vehicle stationary. If clutch-dependent power take-offs areoperated whilst the vehicle is in motion then there may be no gearchanges.

The following safety notes must be observed::

• The power take-off may only be turned on or off with the clutch disengaged.• Disengaging must take place with the engine running at idle speed.• Only turn the power take-off on when the countershaft is stationary. Ratcheting will occur if the powertake-off is turned on with the countershaft rotating

Coast-down times are different depending upon the operating conditions and may be shortened by briefsynchronisation, preferably with 1st gear. Caution: When the vehicle is at rest the pressure in the system slowlydrops. This will cause the jaw clutch coupling located above the pressure spring on the shift cylinder todisengage. As soon as the air pressure in the system increases once more (when the engine is switched on)this will engage again automatically. When the engine is running this will cause damage to the gearchangetoothing leading to premature failure of the power take-off. For this reason therefore, if the vehicle is to beparked for any length of time (e.g. over night) the power take-off must be turned off.

Power take-off designations:

The last letter in the power take-off designation, that is to say the letter „b“ or „c“, indicates the type of output.

A distinction is made between:

• Version "b"

Basic version for shaft drive. Flange in accordance with DIN ISO 7646.

• Version "c"

The simplest and most commonly used type, for direct mounting of a pump. Before installing the pump, theselector sleeve or output gear are placed on the pump drive shaft. The pump connection is in accordance withISO 7653 or BNA NF, R17-102 (e.g. Meiller axial-piston pump).

Version „b“ may possibly be derived from version „c“.


12 of 16 12/16/2012 3:42 PM

Version „c“ can, depending on the type of power take-off, be changed into version „b“.

Fig. 10: Power take-off connection variants ESC-071

If pumps are mounted directly (version “c”), the body building firm must ensure that the maximum permissiblemass moment of a direct-mounted pump with add-on elements (e.g. hoses) is not exceeded::

Table 6: Permissible mass moments at power take-off

Permissible mass moment Power take-off – transmission dependentZF EATON

≤ 30 Nm NL/ 1c, NL/ 4c, N36/ 5c, N850/ 10c2266

290x

≤ 50 Nm NH/ 1c, NH/ 4c, N221/ 10c, NAS/10c, NMAS/ 10c 81Z2

Fig. 11: Maximum mass moment of directly mounted pump ESC-082

Formula 1: Maximum mass moment at power take-off

MG = a • FG

Where:

MG = Maximum mass moment with directly mounted pump from Table 6, in [Nm] a = Distance of pump’s centre of gravity from pump flange face, in [m] FG = Weight of pump including all fittings attached to it, in [N]

7.3.2.3 Engine-dependent power take-offs

Power take-offs with the type designation „NMV“ are engine-dependent. These power take-offs are connecteddirectly to the engine’s crankshaft and thus by-pass the clutch; see Fig. 12. They are rated for continuousoperation and high output. Connection is achieved using an internal, hydraulically actuated multi-disc clutchand the output point can therefore be engaged and disengaged under load.

Fig. 12: ZF power take-offs – NMV layout ESC-072


13 of 16 12/16/2012 3:42 PM

• The NMV can be operated when the vehicle is stationary and when it is in motion.• The NMV is ready for operation as soon as the engine is running.• The transmission of force to the power take-off is fully independent of the vehicle‘s clutch.

There are two basic types: NMV130E on ZF Ecomid transmissions 16S109 (M2000L/M) and NMV221 on the ZFEcosplit transmissions ≥ 16S…. Both of these can be supplied with two different ratios:

Speed factor f = 0,98 • nmot, with max. torque of 2,000Nm Speed factor f = 1,55 • nmot, with max. torque of 1,300Nm

Important operating note on minimum speed during operation:

An operating speed of 800 to 1,200 rpm requires a total moment of inertia (mass moment of inertia) at thepower take-off of > 0,4Kgm2. If the body builder does not know the total moment of inertia/mass moment ofinertia of the equipment he is fitting then an operating speed of > 1,200 rpm should be selected in order toremain above the resonant speed (see Fig. 13). Ideally operation should be within the decoupling limit range orabove it in accordance with Fig. 13.

Fig. 13: ZF NMV power take-off – Influence of total moment of inertia on the resonant speedl ESC-216_3

Fig. 14: ZF NMV power take-offs – graph of engagement speed against mass moment of inertia at the outputflange ESC-167


14 of 16 12/16/2012 3:42 PM

7.3.2.4 Power take-offs on gearboxes with converter lock-up clutch (WSK)

Power take-offs can be attached to gearboxes with a converter lock-up clutch (WSK) in the same way as toother ZF gearboxes. The operation and effect of the NMV itself when attached to a WSK gearbox are nodifferent from its use on a conventional gearbox. Nevertheless, clutch-dependent power take-offs attached toWSK gearboxes differ completely in their function, operation and effect.

If a clutch-dependent power take-off is mounted on a gearbox with WSK, it is essential to take into account thata constant drive ratio is not always maintained. In view of the operating principle of the hydrodynamic torqueconverter, the output speed at the power take-off may vary quite extensively due to slip in the converter.Theoretically the speed at the power take-off could drop as far as zero if the load on the power take-off is largeenough to cause so much slip in the converter that no power can be transmitted. This effect can be avoided byinstalling a bridging circuit, which engages the lock-up clutch automatically when the power take-off isengaged. This creates a rigid mechanical link between the engine and the power take-off, at a constant driveratio. The bridging circuit can be installed only if a gear shift inhibiting circuit is also provided to prevent a gearbeing selected accidentally when the power take-off is engaged.

7.3.2.5 Power take-offs on ZF HP automatic transmissions

The ZF HP 500 and the ZF HP 590 or ZF HP 600 automatic transmissions with torque converter can besupplied with up to two engine speed-dependent power take-offs. The direction of rotation depends on theinstallation position (at right or left of the transmission mainshaft). For this reason the installed position is statedtogether with the power take-off designation. For example, “D02c links” (left) is for installation to the left of themainshaft.Important: This is a reference to the installed position on the transmission, not to the direction of rotation

7.3.2.6 Power take-offs and Intarder

The ZF Intarder is a secondary retarder (an auxiliary hydrodynamic brake) integrated into the gearbox housing.The Intarder is available for gearboxes 12AS… and 16S… and does not restrict the use of power take-offs atthe end of the gearbox.

Some of the power take-offs that can be installed on gearboxes with an Intarder need an adapter kit or arespecially designed power take-offs.

7.3.2.7 Power take-offs for ZF transmissions (Technical data and tables)

na_zf_tab (PDF, 1.700 KB, 03/2009)(_pdf/nebenabtriebe/na_zf_tab_gb.pdf)7.3.2.8 Power take-offs for EATON transmissions (Technical data and tables)


15 of 16 12/16/2012 3:42 PM

na_eaton_tab (PDF, 0.250 KB, 09/2007)(_pdf/nebenabtriebe/na_eaton_tab_gb.pdf)

(#Anchor-16041)

© MAN Truck & Bus AG 2012


16 of 16 12/16/2012 3:42 PM

Documents

Man trucks guidelines for power take offs