Patent Publication Number: US-2009218327-A1

Title: Hydraulically driven tool system

Description:
BACKGROUND 
     The present invention relates generally to work vehicles, and more particularly to arrangements for providing auxiliary support systems in such work vehicles. More particularly, the invention relates to a flexible arrangement for providing electrical power, compressed air service, and/or hydraulic service in a work vehicle. 
     Existing work vehicles often integrate auxiliary resources, such as electrical power, compressed air service, and/or hydraulic service, directly to the mechanical power of the main vehicle engine. Specifically, the main vehicle engine may drive a power take-off shaft, which in turn drives the various integrated auxiliary resources. This is common in many applications where the auxiliary systems are provided as original equipment, either standard with the vehicle or as an option. The work vehicles also may include a clutch or other selective engagement mechanism to enable the selective engagement and disengagement of the integrated auxiliary resources. 
     Unfortunately, these integrated auxiliary resources rely on operation of the main vehicle engine. The main vehicle engine is typically a large engine, which is particularly noisy, significantly over powered for the integrated auxiliary resources, and fuel inefficient. For example, the main vehicle engine may be a spark ignition engine or a compression ignition engine (e.g., diesel engine) having 8, 10, or 12 cylinders. The main vehicle engine may have over 200 horsepower, while the integrated auxiliary resources may only need about 20-40 horsepower. Unfortunately, an operator typically leaves the main vehicle engine idling for extended periods between actual use of the integrated auxiliary resources, simply to maintain the option of using the resources without troubling the operator to start and stop the main vehicle engine. Such operation reduces the overall life of the engine and drive train for vehicle transport needs. 
     BRIEF DESCRIPTION 
     A system, in one embodiment, includes a first service pack module and a second service pack module, wherein the first and second service pack modules are separate from one another. The first service pack module includes a hydraulic motor, an air compressor drivingly coupled to the hydraulic motor, and a generator drivingly coupled to the hydraulic motor. The second service pack module includes an engine, and a hydraulic pump drivingly coupled to the engine. The hydraulic pump also may be configured to supply hydraulic fluid to the hydraulic motor of the first service pack module. A system, in another embodiment, includes a first enclosure, a hydraulic motor, an air compressor drivingly coupled to the hydraulic motor, and a generator drivingly coupled to the hydraulic motor, wherein the hydraulic motor, the air compressor, and the generator are self-contained within the first enclosure without an engine and a hydraulic pump. 
    
    
     
       DRAWINGS 
       These and other features, aspects, and advantages of the present invention will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein: 
         FIG. 1  is a diagram illustrating a work vehicle having first and second service pack modules in accordance with embodiments of the present technique; 
         FIG. 2  is diagram illustrating first and second service pack modules in hydraulic communication with one another in accordance with embodiments of the present technique; 
         FIG. 3  is a diagram illustrating first and second control panels of the respective first and service pack modules as illustrated in  FIG. 2 , in accordance with embodiments of the present technique; 
         FIG. 4  is diagram illustrating first and second service pack modules in hydraulic communication with one another, wherein a fuel tank is external to the service pack modules (i.e., not part of the modules) in accordance with embodiments of the present technique; 
         FIG. 5  is a diagram illustrating an embodiment of the first service pack module as illustrated in  FIGS. 1-4 ; 
         FIG. 6  is a diagram illustrating an embodiment of the second service pack module as illustrated in  FIGS. 1-4 ; and 
         FIG. 7  is a diagram illustrating a work vehicle having the first service pack module as illustrated in  FIGS. 1-5  in accordance with embodiments of the present technique. 
     
    
    
     DETAILED DESCRIPTION 
     Turning now to the drawings,  FIG. 1  illustrates a work vehicle  10  including a main vehicle engine  12 , first and second service pack modules  18  and  22 , and various equipment in accordance with certain embodiments of the present technique. As discussed in further detail below, the first and second service pack modules  18  and  22  may provide various resources, such as electrical power, compressed air, and hydraulic power, with or without assistance from the main vehicle engine  12 . Thus, in some embodiments, the operator can shut off the main vehicle engine to reduce noise, conserve fuel, and increase the life of the main vehicle engine  12 , while the service pack modules  18  and  22  are self-powered or power one another. However, in some embodiments, the service pack modules  18  and  22  may utilize and/or provide some resources of the vehicle  10 , e.g., use fuel from the vehicle, use hydraulic power from the vehicle, provide hydraulic power to the vehicle, and so forth. The illustrated work vehicle  10  is a work truck, yet other embodiments of the vehicle may include other types and configurations of vehicles. 
     The main vehicle engine  12  may include a spark ignition engine (e.g., gasoline fueled internal combustion engine) or a compression ignition engine (e.g., a diesel fueled engine), for example, an engine with 8, 10, or 12 cylinders with over 200 horsepower. The vehicle engine  12  includes a number of support systems. For example, the vehicle engine  12  consumes fuel from a fuel reservoir, typically one or more liquid fuel tanks, which will be addressed later. Further, the vehicle engine  12  may include or couple to an engine cooling system, which may include a radiator, circulation pump, thermostat controlled valve, and a fan. The vehicle engine  12  also includes an electrical system, which may include an alternator or generator along with one or more system batteries, cable assemblies routing power to a fuse box or other distribution system, and so forth. The vehicle engine  12  also includes an oil lubrication system. Further, the vehicle engine  12  also couples to an exhaust system, which may include catalytic converters, mufflers, and associated conduits. Finally, the vehicle engine may feature an air intake system, which may include filters, flow measurement devices, and associated conduits. 
     The service pack modules  18  and  22  may have a variety of resources, such as electrical power, compressed air, hydraulic power, and so forth. These service pack modules  18  and  22  also may operate alone or in combination with one another, e.g., dependent on one another. In the illustrated embodiment, the first service pack module  18  includes a service pack engine  14  and a hydraulic pump  16 . The service pack engine  14  may include a spark ignition engine (e.g., gasoline fueled internal combustion engine) or a compression ignition engine (e.g., a diesel fueled engine), for example, an engine with 1-4 cylinders with 10-80 horsepower. The hydraulic pump  16  is configured to provide hydraulic power (e.g., pressurized hydraulic fluid) to one or more devices in the vehicle or elsewhere. The hydraulic pump  16  may be based on any suitable technology, such as piston pumps, gear pumps, vane pumps, with or without closed loop control of pressure and/or flow. 
     As illustrated in the embodiment of  FIG. 1 , the first and second service pack modules  18  and  22  are separate from one another and from vehicle engine  12 . In other words, the first and second service pack modules  18  and  22  are stand-alone units relative to the vehicle engine  12 , such that they do not rely on power from the vehicle engine  12 . However, in the illustrated embodiment, the second service pack module  22  is driven by hydraulic fluid from the first service pack module  18 , thereby making the second service pack module  22  dependent on the first service pack module  18  or another source of hydraulic fluid. Specifically, as illustrated in  FIG. 1 , the service pack engine  14  drives a hydraulic pump  16 , which in turn drives hydraulic motor  24  located in second service pack module  22 . 
     The hydraulic motor  24  contained in second service pack module  22  may be coupled to air compressor  26  as well as generator  28 . The air compressor  26  and the generator  28  may be driven directly, or may be belt, gear, or chain driven, by the hydraulic motor  24 . The generator  28  may include a three-phase brushless type, capable of producing power for a wide range of applications. However, other generators may be employed, including single phase generators and generators capable of producing multiple power outputs. The air compressor  26  may also be of any suitable type, although a rotary screw air compressor is presently contemplated due to its superior output to size ratio. Other suitable air compressors might include reciprocating compressors, typically based upon one or more reciprocating pistons. 
     The first and/or second service pack modules  18  and  22  include conduits, wiring, tubing, and so forth for conveying the services/resources (e.g., electrical power, compressed air, and hydraulic power) generated by these modules to an access panel  30 . The access panel  30  may be located on any portion of the vehicle  10 , or on multiple locations in the vehicle, and may be covered by doors or other protective structures. In one embodiment, all of the services may be routed to a single/common access panel  30 . The access panel  30  may include various control inputs, indicators, displays, electrical outputs, pneumatic outputs, and so forth. In an embodiment, a user input may include a knob or button configured for a mode of operation, an output level or type, etc. In the illustrated embodiment, the first and second service pack modules  18  and  22  supply electrical power, compressed air, and hydraulic power to a range of applications designated generally by arrows  32 . 
     As depicted, air tool  34 , torch  36 , and light  38  are applications connected to the access panel  30  and, thus, the resources/services provided by the service pack modules  18  and  22 . The various tools may connect with the access panel  30  via electrical cables, gas (e.g., air) conduits, and so forth. The air tool  34  may include a pneumatically driven wrench, drill, spray gun, or other types of air-based tools, which receive compressed air from the access panel  30  and compressor  26  via a supply conduit (e.g., a flexible rubber hose). The torch  36  may utilize electrical power and compressed gas (e.g., air or inert shielding gas) depending on the particular type and configuration of the torch  36 . For example, the torch  36  may include a welding torch, a cutting torch, a ground cable, and so forth. More specifically, the welding torch  36  may include a TIG (tungsten inert gas) torch or a MIG (metal inert gas) gun. The cutting torch  36  may include a plasma cutting torch and/or an induction heating circuit. Moreover, a welding wire feeder may receive electrical power from the access panel  30 . Moreover, a hydraulically powered vehicle stabilizer  40  may be powered by the hydraulic system, e.g., hydraulic pump  16 , to stabilize the work vehicle  10  at a work site. In the illustration, a hydraulically powered crane  42  is also coupled to and powered by the hydraulic pump  16 . Again, the service pack modules  18  and  22  provide the desired resources/services to run various tools and equipment without requiring operation of the main vehicle engine  12 . 
     As noted above, the disclosed service pack modules  18  and  22  may be designed to interface with any desired type of vehicle. Such vehicles may include cranes, manlifts, and so forth, which can be powered by the service pack modules  18  and/or  22 . In the embodiment of  FIG. 1 , the crane  42  may be mounted within a bed of the vehicle  10 , on a work platform of the vehicle  10 , or on an upper support structure of the vehicle  10  as shown in  FIG. 1 . Moreover, such cranes may be mechanical, electrical or hydraulically powered. In the illustrated embodiment, the crane  42  can be powered by the service pack modules  18  and/or  22  without relying on the vehicle engine  12 . That is, once the vehicle is positioned at the work site, the vehicle engine  12  may be stopped and the service pack engine  14  may be started for crane operation and use of auxiliary services. In the embodiment illustrated in  FIG. 1 , the crane  42  is mounted on a rotating support structure, and hydraulically powered such that it may be rotated, raised and lowered, and extended (as indicated by arrows  44 ,  46  and  48 , respectively) by pressurized hydraulic fluid provided by the service pack output  32 . 
     The vehicle  10  and/or the service pack modules  18  and  22  may include a variety of protective circuits for the electrical power, e.g., fuses, circuit breakers, and so forth, as well as valving for the hydraulic and air service. For the supply of electrical power, certain types of power may be conditioned (e.g., smoothed, filtered, etc.), and 12 volt power output may be provided by rectification, filtering and regulating of AC output. Valving for hydraulic power output may include by way example, pressure relief valves, check valves, shut-off valves, as well as directional control valving. Moreover, the hydraulic pump  16  may draw fluid from and return fluid to a fluid reservoir, which may include an appropriate vent for the exchange of air during use with the interior volume of the reservoir, as well as a strainer or filter for the hydraulic fluid. Similarly, the air compressor  26  may draw air from the environment through an air filter. 
     The first and second service pack modules  18  and  22  may be physically positioned at any suitable location in the vehicle  10 . In a presently contemplated embodiment, for example, the service pack modules  18  and  22  may be mounted on, beneath or beside the vehicle bed or work platform rear of the vehicle cab. In many such vehicles, for example, the vehicle chassis may provide convenient mechanical support for the engine and certain of the other components of the service pack modules  18  and  22 . For example, steel tubing, rails or other support structures extending between front and rear axles of the vehicle may serve as a support for the service pack modules  18  and  22  and, specifically, the components self-contained in those modules. Depending upon the system components selected and the placement of the service pack modules  18  and  22 , reservoirs may be provided for storing hydraulic fluid and pressurized air as noted above. However, the hydraulic reservoir may be placed at various locations or even integrated into the service pack modules  18  and/or  22 . Likewise, depending upon the air compressor selected, no reservoir may be used for compressed air. Specifically, if the air compressor  26  includes a non-reciprocating or rotary type compressor, then the system may be tankless with regard to the compressed air. 
     In use, the service pack modules  18  and  22  provide various resources/services (e.g., electrical power, compressed air, hydraulic power, etc.) for the on-site applications completely independent of vehicle engine  12 . For example, the service pack engine  14  generally may not be powered during transit of the vehicle from one service location to another, or from a service garage or facility to a service site. Once located at the service site, the vehicle  10  may be parked at a convenient location, and the main vehicle engine  12  may be shut down. The service pack engine  14  may then be powered to provide auxiliary service from one or more of the service systems described above. Where desired, clutches, gears, or other mechanical engagement devices may be provided for engagement and disengagement of one or more of the generator  28 , the hydraulic pump  16 , and the air compressor  26 , depending upon which of these service are desired. Moreover, as in conventional vehicles, where stabilization of the vehicle or any of the systems is require, the vehicle may include outriggers, stabilizers, and so forth which may be deployed after parking the vehicle and prior to operation of the service pack modules. The disclosed embodiments thus allow for a service to be provided in several different manners and by several different systems without the need to operate the main vehicle engine  12  at a service site. 
     Several different arrangements are envisaged for the components of the first service pack module  18  and the second service pack module  22 .  FIG. 2  illustrates an embodiment of the first and second service pack modules  18  and  22 , wherein the first service pack module  18  includes the service pack engine  14 , the hydraulic pump  16 , and a fuel tank  50 , and wherein the second service pack module  22  includes the hydraulic motor  24 , the air compressor  26 , and the generator  28 . As discussed below, the components of each service pack modules  18  and  22  are self-contained in respective enclosures  49  and  51 , such that the modules  18  and  22  are independent and distinct from one another. In other words, the enclosure  49  of the module  18  self contains the engine  14 , the hydraulic pump  16 , and the fuel tank  50  independent of both the module  22  and various components of the vehicle  10 . Similarly, the enclosure  51  of the module  22  self contains the hydraulic motor  24 , the air compressor  26 , and the generator  28  independent of both the module  18  and various components of the vehicle  10 . 
     In some embodiments, each module  18  and  22  may be described as consisting essentially of the components shown in  FIG. 2 . For example, the first service pack module  18  may be described as consisting essentially of the enclosure  49 , the engine  14  within the enclosure  49 , the hydraulic pump  16  within the enclosure  49 , and the fuel tank  50  within the enclosure  49 . Thus, the first service pack module  18  may be described as not including one or more of the components provided in the second service pack module  22  (e.g., the hydraulic motor  24 , the air compressor  26 , and/or the generator  28 ). By further example, the second service pack module  22  may be described as consisting essentially of the enclosure  51 , the hydraulic motor  24  within the enclosure  51 , the air compressor  26  within the enclosure  51 , and the generator  28  within the enclosure  51 . However, in the illustrated embodiment of  FIG. 2 , the second service pack module  22  may be described as consisting essentially of the enclosure  51 , the hydraulic motor  24  within the enclosure  51 , the air compressor  26  within the enclosure  51 , the generator  28  within the enclosure  51 , and also a welding/cutting circuit  58  within the enclosure  51 . Thus, the second service pack module  22  may be described as not including one or more of the components provided in the first service pack module  18  (e.g., engine  14 , the hydraulic pump  16 , and/or the fuel tank  50 ). Specifically, in the embodiment shown in  FIG. 2 , the second service pack module  22  does not include an engine (e.g., a fuel-powered engine) and a hydraulic pump. 
     Moreover, the service pack modules  18  and  22  may be used independently or in combination with one another. For example, the first service pack module  18  may be used to provide hydraulic power for any type of hydraulically driven system, which may or may not include the second service pack module  22 . In certain embodiments, the first service pack module  18  may be described as dependent only on a source of fuel, such as gasoline or diesel fuel, to operate the engine  14  and provide the hydraulic power. By further example, the second service pack module  22  may be hydraulically driven by any suitable source of hydraulic power, which may or may not include the hydraulic pump  16  of the first service pack module  18 . Thus, in certain embodiments, the second service pack module  22  may be described as hydraulically dependent on some source of hydraulic power, or more specifically, only hydraulic power dependence. 
     As appreciated, the separation of these various components (e.g.,  14 ,  16 ,  24 ,  26 ,  28 ,  50 , and  50 ) into multiple stand-alone modules (e.g.,  18  and  22 ) enables a more flexible use of these services/resources in various applications. For example, if the application already has a source of hydraulic power, then the second service pack module  22  is particularly useful without the need for the first service pack module  18 . Similarly, if the application already has a source of electrical power and/or compressed air but no source of hydraulic power, then the first service pack module  18  is particularly useful without the need for the second service pack module  18 . In contrast, if a single unit incorporated all of the components (e.g.,  14 ,  16 ,  24 ,  26 ,  28 ,  50 , and  50 ), then the application may end up with redundant resources. As a result, the separation of the components (e.g.,  14 ,  16 ,  24 ,  26 ,  28 ,  50 , and  50 ) into the modules  18  and  22  not only provides for a more flexible approach, but it also reduces the cost, size, weight, and complexity of each individual module  18  and  22 . 
     Turning now to the details of  FIG. 2 , the first service pack module  18  includes a first service access panel  52 , which includes hydraulic couplings  53  to output hydraulic fluid from the hydraulic pump  16  to various external devices. In the illustrated embodiment, the hydraulic couplings  53  couple to the second service pack module  22 , the hydraulic crane  42 , a hydraulic tool  54 , hydraulic equipment  56 , and the hydraulic stabilizer  40 . For example, the second service pack module  22  is connected to the first service pack module  18  via hydraulic tubing  20  connected to one of the couplings  53 . 
     As further illustrated in  FIG. 2 , the second service pack module  22  includes the hydraulic motor  24  coupled to the air compressor  26  and generator  28 , which is connected to the welding/cutting circuit  58 . The circuit  58  may include one or more circuits configured to provide power, functions, and control for welding, cutting, wire feeding, gas supply, and so forth. The generator  28  may provide electrical power to the welding circuit  58  to operate various welding devices, such as those discussed above. The second service pack module  22  also includes a service pack access panel (e.g.,  30 ), which includes couplings  59  (e.g., electrical, air, and optionally hydraulic connectors) for various external devices. For example, the service pack module  22  may or may not provide hydraulic couplings  59  as a pass through from the hydraulic fluid received into the system. Connections to access panel  30  may provide service to several tools, including hydraulic tool  60 , air tool  62 , electric tool  64 , air tool (e.g., wrench)  34 , torch  36 , and light  38 . In addition, the various external devices include electrical cables, air hoses, hydraulic tubing, and so forth, as illustrated by the lines extending between the devices and their respective couplings  59  on the panel  30 . The access panel  30  also may include one or more controls  65  for the various services/resources, e.g., electrical power, compressed air, hydraulics, etc. As discussed below, these controls  65  may include input controls (e.g., switches, selectors, keypads, etc.) and output displays, gauges, and the like. 
     As appreciated, the generator  28  and/or circuit  58  may be configured to provide AC power, DC power, or both, for various applications. Moreover, the circuit  58  may function to provide constant current or constant voltage regulated power suitable for a welding or cutting application. Thus, the torch  36  may be a welding torch  36 , such as a MIG welding torch, a TIG welding torch, and so forth. The torch  36  also may be a cutting torch, such as a plasma cutting torch. The generator  28  and/or circuit  58  also may provide a variety of output voltages and currents suitable for different applications. For example, a 12 volt DC output of the module  22  may also serve to maintain the vehicle battery charge, and to power any ancillary loads that the operator may need during work (e.g., cab lights, hydraulic system controls, etc.). 
       FIG. 3  illustrates an embodiment of the access panels  30  and  52  of the respective first and second service pack modules  18  and  22 , as shown in  FIGS. 1 and 2 . In the illustrated embodiment, the access panel  30  of the module  22  includes the various couplings  59  and controls  65  shown in  FIG. 2 . Specifically, the couplings include a set of air couplings  59 A, a set of electrical power couplings  59 B, and a set of torch couplings  59 C. The controls  65  include a voltage gauge  66  and associated voltage control knob  67 , a current gauge  68  and associated current control knob  69 , an air pressure gauge  70  and associated pressure control knob  71 , and a display screen  72  (e.g., liquid crystal display) and associated input keys  73 . The controls  65  also may include on/off switches or buttons  75  for each of the couplings  59 , such that an operator can turn on and off the electrical power, the compressed air, and/or the hydraulic power linked to the couplings  59 A,  59 B, and  59 C. Optionally, the access panel  30  may include various hydraulic couplings, gauges, and controls in an embodiment that routes at least some of the hydraulic fluid from the first module  18  through the second module  22  to various external hydraulic devices. Furthermore, the access panel  30  may be used as a central control panel for all resources/services provided by both modules  18  and  22  when these modules  18  and  22  are used in combination with one another. 
     In the illustrated embodiment, the access panel  52  may include several hydraulic output couplings  52  as well as hydraulic and power controls to monitor and configure settings for service pack engine  14  and hydraulic pump  16 . The access panel  52  may also permit, for example, starting and stopping of the service pack engine  14  by a keyed ignition or starter button. The access panel  52  may also include a stop, disconnect, or disable switch that allows the operator to prevent starting of the service pack engine  14 , such as during transport. The access panel  52  may also include hydraulic pressure gauge  74 , engine RPM gauge  76 , engine fuel gauge  78 , engine temperature gauge  80 , and various inputs and outputs as generally depicted by numeral  82 . 
       FIG. 4  depicts another embodiment of first service pack module  18  and second service pack module  22 . As shown, first service pack module  18  includes service pack engine  14  as well as hydraulic pump  16 . Fuel tank  50  is located outside the enclosure for first service pack module  18 . In the present embodiment, fuel tank  50  may be shared with and used by vehicle engine  12 . Alternatively, fuel tank  50  may be dedicated to service pack engine  14 . In the present embodiment, first service pack module  18  is coupled to second service pack module  22  via hydraulic tubing  20 . Second service pack module  22  includes generator  28 , hydraulic motor  24 , and air compressor  26 . In certain embodiments, as illustrated in  FIG. 4 , the first service pack module  18  consists essentially of service pack engine  14  and hydraulic pump  16 . In other words, in the present embodiment, the first service pack module  18  does not include fuel tank  50 , the hydraulic motor  24 , the air compressor  26 , and the generator  28 . Similarly, in certain embodiments as illustrated in  FIG. 4 , the second service pack module  22  consists essentially of generator  28 , hydraulic motor  24 , and air compressor  26 . In other words, in the present embodiment, the second service pack module  22  excludes the engine  14  and the hydraulic pump  16  among other things. 
       FIG. 5  shows an embodiment of second service pack module  22  which includes air compressor  26 , generator  28 , welding circuit  58 , and hydraulic motor  24 . In the illustrated embodiment, hydraulic motor  24  drives generator  28  and air compressor  26  via a belt drive system  84 . Hydraulic motor  24 , generator  28 , and air compressor  26  may be connected to belt drive system  84  via drive connections  86 . Drive connections  86  couple the components to the belt drive system  84  and may include shafts, pulleys, gears, clutches, or any combination thereof. 
       FIG. 6  is an illustration of an embodiment of first service pack module  18 . First service pack module  18  includes service pack engine  14 , generator  28 , and hydraulic pump  16 . In the present embodiment, service pack engine  14  is coupled to hydraulic pump  16  and generator  28  via belt drive system  88 . Belt drive system  88  may be coupled to the components via drive connections  90 . Drive connections  90  may include clutches, gears, shafts, pulleys, or any combination thereof. Also shown in the diagram is fuel tank  50 , contained within first service pack module  18 . In this particular embodiment, the first service pack module  18  may output hydraulic power as well as electric power. In certain embodiments, as illustrated in  FIG. 6 , the first service pack module  18  consists essentially of service pack engine  14 , hydraulic pump  16 , generator  28 , fuel tank  50 , and belt drive system  88 . In other embodiments, the first service pack module  18  consists essentially of service pack engine  14 , hydraulic pump  16 , generator  28 , and fuel tank  50 . In further embodiments, the first service pack module  18  consists essentially of service pack engine  14 , hydraulic pump  16 , and generator  28  (e.g., without fuel tank  50 ). 
     Referring to  FIGS. 5 and 6 , one or more belts and/or clutches may be drivingly coupled between these components, and an idler may also be provided for maintaining tension on the belt. For example, a clutch (e.g., an electrically powered clutch) may be used to selectively engage and disengage any of the illustrated components to allow for separate control of the components. Such control may be useful for controlling the power draw on the engine and/or hydraulic motor, particularly when no load is drawn from the particular component. As may be contemplated, more than one belt may be provided on appropriate multi-belt pulleys, where the torque for turning the components is greater than that available from a single belt. Other arrangements, such as chain drives, are also be envisaged. Moreover, as described above, the generator  28  may be belt or chain driven, or more than one component may be driven directly by the hydraulic motor  24  or the service pack engine  14 , such as in an in-line configuration. In a further alternative arrangement, one or more of the components may be gear driven, with gearing providing any required increase or decrease in rotational speed from the output speed of the engine. The particular component or components that are directly and/or indirectly driven by the hydraulic motor or engine may be selected based upon specifications. 
       FIG. 7  is a block diagram illustrating an alternative configuration of service pack module  22  without service pack module  18  within the work vehicle  10 . In the illustrated embodiment, the vehicle engine  12  directly drives hydraulic pump  16  via engine power take-off (PTO) shaft  92 . A clutch or other selective engagement mechanism may be provided to enable the hydraulic pump  16  to be driven when desired and disengaged from the vehicle engine  12  when vehicle  10  is in transport to a work site. In the present embodiment, hydraulic pump  16  is connected via hydraulic tubing  94  to hydraulic motor  24 , which is a component of second service pack module  22 . Second service pack module  22  includes hydraulic motor  24 , air compressor  26 , and generator  28 . As illustrated, second power module  22  receives hydraulic power from hydraulic pump  16 , which is driven by vehicle engine  12 , instead of a separate service pack engine, as shown in previous embodiments. 
     Several different scenarios are envisaged for arrangement of the components of the service pack modules  18  and  22 , and for integrating or separating the support systems and components of the service pack modules from those of the vehicle  10 . Thus, the elements contained in the modules discussed above may be added or removed, and/or rearranged, depending upon application-specific and other constraints. For example, second service pack module  22  of  FIG. 2  may be combined with first service pack module  18  of  FIG. 4  to deliver desired services on a work vehicle. 
     In some embodiments, which are not illustrated, some of the support systems for the vehicle engine  12  may be used to support the service pack engine  14 , and vice-versa. For example, at least the fuel supply and electrical systems may be at least partially integrated to reduce the redundancy of these support systems in the work vehicle. The electrical system of the service pack modules may service certain support needs when the vehicle engine  12  is turned off, such as providing 12V power to vehicle accessories and charging the vehicle batteries. Similarly, heating, ventilating and air conditioning systems may be supported by the service pack engine  14 , to provide heating of the vehicle cab when the vehicle engine  12  is turned off. Finally, a fuel conduit may draw fuel from the reservoir/tank of the vehicle engine  12  to supply fuel to the service pack engine  14 . Further, more or less integration and removal of redundancy is possible. 
     While only certain features of the invention have been illustrated and described herein, many modifications and changes will occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention.