Modular Drive Systems
Modular Drive Systems
Modular Drive Systems
67
Bartosz STACHURA
Abstract. This article describes some of the modern drive systems primarily designed for use in
military technology. The main features of the power-pack type systems are discussed along with their structure.
The most important technical parameters are listed on the basis of selected examples of Polish applications. In
addition, tables are provided with known examples of implemented applications of modular drive systems in
land vehicles: armoured personnel carriers and tanks.
Keywords: modular drive systems, power-pack, engine, transmission, gearbox, tank, military vehicle.
1. INTRODUCTION
Manufacturers of the best known and leading military land vehicles were forced to
convert conventional drive systems into power-pack type modular drive systems. One of the
reasons for this was the need for fast dismantling of the damaged component and installation
of a new one in the shortest possible time, so as not to disrupt the combat momentum, and
above all to ensure the safety not only of the vehicle crew, but also of the maintenance
personnel.
The newly designed military land vehicles are mostly provided with modular
power-pack type drive systems which have a number of advantages, as described later in this
paper.
The power transmission system of a modern military tracked vehicle should make the
most of the engine characteristics, and of the torque transferred to the tracks dependent on the
resistance to motion of the vehicle. This can be achieved by applying, preferably in an
automatic manner, appropriate transmission ratio adapted to travel speed and terrain
conditions. Another important task of the drive unit is to enable steering of the vehicle at a
turning radius set by the driver, as is the case, for instance, in wheeled vehicles. Currently, the
most commonly used design is a drive system with automatic transmission and hydrostatic
steering mechanism that ensures controllability both when driving in straight line, as well as
when changing direction. Therefore the main task of the designer of a modern tracked vehicle
is to develop a power transmission system which should provide:
any turning radius set by the driver, that radius being independent of changes in
ambient conditions, engine speed, engine load or driving resistance;
good vehicle steerability;
high efficiency of power transmission;
maintaining the set straight driving direction irrespective of changes in track motion
resistance;
optimum utilization of engine performance under varying loads.
Power transmission systems used in modern military vehicles, both wheeled and
tracked, may generally be classified into the following groups:
mechanical;
hydromechanical;
electromechanical;
electrical.
Mechanical drive is the simplest solution, historically the most widely used, easy to
operate, but absorbing much of driver's attention while moving over rough terrain or under
combat conditions. In order to improve the comfort of operating modern military vehicles,
hydromechanical automatic gearboxes are used, and in the case of tracked vehicles,
hydromechanical gearboxes with hydrostatic steering mechanisms. Recently there is also
renewed interest in electric/diesel or hybrid drives in military equipment. The efficiency of
electric drives is high as compared to that of hydromechanical drives [1].
Land vehicles with conventional power transmission systems are now slowly being
consigned to history. These systems, despite their undeniable reliability and often
uncomplicated design, are supplanted by power-pack type drive systems.
Fig. 1. Conventional drive system of the ANDERS Fire Support Vehicle [17,18]
Table 1 below lists the basic dimension and weight specifications of the drive system
of FSV.
Table 1. Weight and dimensions of the drive system of FSV Anders [18,19]
1 reverse gear
functionally complete structure. The drive system is mounted on the frame together with all
appurtenances, including the fuel, oil and air filters, exhaust silencer and cooling system with
hydrostatic pumps, hydraulic motors and radiator fans. An excellent example of a modular
drive system is the Puma Infantry Fighting Vehicle shown below in Fig. 2. The vehicle
constitutes a novel weapons system which had substantially strengthened the German armed
forces. The vehicle carries three crew members in one air-conditioned compartment
(commander, driver, gunner) and up to six landing party soldiers in the rear of the vehicle
where a rear exit hatch is located. A tight separation of the drive compartment from the crew
compartment reduced noise by 90% as compared to Marder 2 [3] (down to 95 dB) [4].
Cooling system radiators
Starter generator
Fig. 2. Complete drive system of IFV Puma [4]
IFV Puma is powered with a 10-cylinder MTU (HPD) 890 engine. This engine is
compact and lightweight. Despite this it produces an output of 1100 hp. The new HPD type
engine is the key unit in the general concept of the Puma vehicle. Reduced space requirements
for the drive system also contribute to lower vehicle weight, which enables putting on a
heavier armour [5].
A modular drive system is characterized by:
ability to rapidly replace the entire system in case of failure and to repair the faulty
system and bring it to full working condition - replacement of the drive system
takes about an hour, which is of paramount importance under combat conditions;
automatic gear change ensures optimum utilization of the power and torque of the
engine;
control system extends failure-free operation time of the drive system;
steering using a steering wheel.
Modular drive systems 71
Travel direction
Engine compartment
Power pack
Partition
Driver compartment
Driver
A Polish example of such system is the power pack created as a concept of the Infantry
Fighting Vehicle. It is, however, at an initial stage of development, therefore it lacks some
components on the common frame, e.g.: cooling system, etc.
The conceptual design of the Infantry Fighting Vehicle [14] was created in 2012 at OBRUM
Gliwice.
Fig. 4 shows a drive system designed for the infantry fighting vehicle. The engine used
for this vehicle is MTU 8V 199 TE20 [6,15].
72 Bartosz STACHURA
Fig. 4. Power-pack MTU 8V 199 TE20 engine with X300 transmission [16]
In this arrangement the engine is parallel to the transmission. The units are connected by
means of an intersecting axis intermediate gear, usually having a 1:1 ratio. The power-pack is
U-shaped, and therefore it is often mounted in the rear part of the chassis. There is less load
on the front of the vehicle, which improves driving performance in marshy terrain.
Travel direction
Engine compartment
Main engine
Fig. 6 shows a modular drive system installed on the PT-91M tank designed for the
Malaysian army based on PT-91 tank with conventional drive system.
Fig. 7. Renk ESM350 transmission [2] Fig. 8. WOLA S1000 engine [13]
Vehicle
Modular drive systems
OF WESTERN MANU
Crew 3 +7 3 +6 3 +6 3 +7 3 +7
31,500 t (level A)
Weight (kg) up to 40,000 23,000 (combat) 28,200 (combat) 25,400
43,000 (level C)
Scania V8 14 litre (or 6-cylinder IvecoFiat Perkins V-8 Condor
Engine MTU V10 892 MTU MB Ea-500
16 litre) 8260 Diesel
Output (kW) 808 1073 512 600 hp 550
Output/Weight 34.1 (level A)
20.2 22.6 21.3 23.5
(hp/t) 25 (level C)
Max. speed (km/h) 70 70 70 75 75
Driving range 900 600 500 520 660
Manufacturer Sweden Germany Italy Germany United Kingdom
Development upgrades upgrades upgrades upgrades upgrades
EXAMPLES OF POWER-PACKS USED IN INFANTRY FIGHTING VEHICLES
75
Bartosz STACHURA
5.
76
Vehicle
MANUFACTURE
Crew 4 3 4 3 4
Weight (kg) 64,000/65,000 50,200 62,300 54,500 62,500
AVDS-1790-9AR / Mitsubishi 10ZG
Engine MTU MB873 KA501 UDV8X-1500 CV12 Perkins Condor
GD833 (2-stroke)
Output (kW) 1500 1500 1521 1496 1200
Output/Weight
19.67/23.07 30 24.1 27.52 19.2
(hp/t)
Max. speed (km/h) 55 70 72 72 59
Driving range 500 400 550 550/650 450
Manufacturer Israel Japan Germany France United Kingdom
EXAMPLES OF POWER-PACKS USED IN TANKS OF WESTERN
6. CONCLUSIONS
Modern modular power-pack type drive systems replace conventional drive systems.
Many armies (users of land vehicles) upgrade their equipment and replace conventional
drive systems with power-packs.
Dimensions of conventional drive systems are often much larger than those of modular
power-pack type systems.
Choice between the L- and U-shaped power-pack takes place at the beginning of the design
work, when decisions are made during the drawing up of Tactical and Technical Guidelines
which system will be optimal for the given type of vehicle.
Gear changing in the power-pack is automatic, which ensures optimum utilization of the
power and torque of the engine.
In the case of failure of the modular drive system, the entire system can be replaced quickly.
It is then repaired to retain full operability.
Replacement of the modular drive system takes about an hour, which is of paramount
importance under combat conditions. Short replacement time improves the safety of the
vehicle crew and of the maintenance personnel.
Automatic control system applied in power-packs extends failure-free operation time of the
drive system.
Steering a vehicle with a power-pack is by means of a steering wheel, which improves
driving ergonomics.
8. REFERENCES
[1] Myk A., Skowron K.: Rozwj ukadw przeniesienia napdw w pojazdach
gsienicowych, Szybkobiene Pojazdy Gsienicowe nr 3 (31), Gliwice 2012
[2] http://pl.wikipedia.org/ Ukad przeniesienia napdu/ 08.10.2014.
[3] http://pl.wikipedia.org/ Marder 2/ 15.10.2014.
[4] http://pl.wikipedia.org/ Puma (bojowy wz piechoty/ 02.12.2014.
[5] Mura G., Myk P.: Silniki wspczesnych gsienicowych bojowych wozw piechoty,
Szybkobiene Pojazdy Gsienicowe nr 1 (29), Gliwice 2012.
[6] http://www.mtu-online.com/ MTU Friedrichshafen GmbH/ 20.08.2014.
[7] http://www.scania.com/ SCANIA Group/ 15.12.2014.
[8] http://pl.wikipedia.org/ Bojowy Wz Piechoty/ 10.11.2014.
[9] Holota M., Kurpas M., Olek J., Synowiec M.: Wspczesne bojowe wozy
piechoty, Szybkobiene Pojazdy Gsienicowe nr 3 (31), Gliwice 2012.
[10] http://en.wikipedia.org/ PTO - Power_take-off / 12.12.2014.
[11] http://pl.wikipedia.org/ Przystawka_odbioru_mocy / 02.01.2015.
[12] http://www.armedforces-int.com/ X300-12.pdf./ 10.11.2014.
[13] http://www.pzl-wola.pl/ 15.09.2014.
[14] Lekki czog na bazie wielozadaniowej platformy bojowej analiza moliwoci
zastosowania podwozia czogu lekkiego do celw wielozadaniowych. WAT. January
June 2010. Unpublished.
78 Bartosz STACHURA
[15] Szulborski A.: Silniki MTU jako przyszy napd pojazdw grupy BUMAR. Aspekty
techniczne i produkcyjne, Warszawa, 21.11.2011r.
[16] http://www.allisontransmission.com/ 10.12.2014.
[17] Holota M., Stachura B.: Polska platforma bojowa XXI wieku baz nowej rodziny
pojazdw specjalistycznych, Szybkobiene Pojazdy Gsienicowe (28) nr 1, Gliwice
2012.
[18] http://gdziewojsko.wordpress.com/ Wozy Bojowe Anders /, 10.12.2014.
[19] http://www.altair.com.pl/ WWO Anders / 18.09.2013.