Abstract:
A trailer mounts a turbine and a generator for transport to a power generation site. The mount for the turbine includes a sub-base mounted for pivotal movement adjacent a rear end thereof proximate the forward end of the generator. The forward end of the sub-base is secured to the trailer by an isolator mount. The two mounts constitute a 3-point mounting system for the sub-base and turbine carried thereby whereby during transport, the sub-base and turbine are enabled for limited angular deflection of the turbine axis relative to the generator rotor axis. The pivotal mounting adjacent the interconnection between the turbine and generator rotors lies along discrete opposite sides of the trailer. Torque is transmitted from the turbine to the generator base through the pivotal mountings. At the power generation site, the sub-base is locked down and minimal adjustment is required to align the turbine and generator rotors.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a mobile power generating unit and particularly relates to a system for mounting a turbine and an electromotive machine, with their rotor axes in substantial alignment with one another, on a trailer for over-the-road transport whereby alignment adjustments at the power generating site are minimized. 
     Mobile power generating units are well known and typically comprise a turbine and an electromotive machine such as a generator or alternator (herein referred to interchangeably as a generator) mounted either on separate trailers or a single trailer for transport to a power generating site. Typically, the turbine and generator are mounted on different trailers. At the site, the turbine and generator are coupled to one another to form the power generating unit. It will be appreciated that these units are large-scale, heavy and require accurate alignment in use in order to safely and efficiently generate power. This often necessitates deployment of heavy-duty equipment to manipulate one or both of the machines into alignment at the site and, as a result, requires substantial investment in time and labor. Not infrequently, a full week may be required to properly align and adjust the machines for operation. In those power generation units mounting the turbine and generator on a single trailer, the rotors of the turbine and generator are typically connected together by a flexible coupling. While the turbine and generator are in initial alignment prior to transport, it is very difficult to maintain alignment during travel and also to correct for misalignment at start-up, i.e., difficult to realign. This is in part due to the manner of mounting the turbine and generator on the trailering system. 
     Additionally, with the turbine and generator mounted directly on a single trailer and generating power at the site, torque from the turbine is transmitted directly to the trailer. Because the trailer is not constructed to accommodate torque, the power generating system gradually and unpredictably goes out of alignment. 
     Accordingly, there has arisen a need for a power generating unit of substantial size and power generating capacity having a capability for over-road transport of the turbine and generator on a single trailer with the drive line initially aligned and enabling angular deflection during transport with minimal alignment adjustments at start-up and reduced capacity for misalignment during operation. 
     BRIEF SUMMARY OF THE INVENTION 
     In accordance with a preferred embodiment of the present invention, there is provided a single trailer for transporting an initially aligned turbine and electromotive machine such as a generator or alternator (hereafter referred to as a generator) over-road to a power generation site whereby the system can be readily aligned at the site and maintained in alignment during operation. To accomplish this, the generator is fixed to the trailer. Preferably, the base of the generator is welded to the frame of the trailer, fixing the component parts of the machine, both stationary and rotational components, in exact position. The turbine, however, is fixed to a sub-base. The sub-base, in turn, is pivotally mounted at one end to the generator base, preferably by a pair of transversely spaced clevis mounts. The opposite end of the sub-base is mounted to an isolator fixed to the trailer frame along the centerline of the trailer. This 3-point mounting, i.e., the isolator and the pair of clevis mounts, enable angular deflection of the axis of the turbine relative to the axis of the rotor of the generator during transport. The isolator is, of course, locked down to maintain alignment of the turbine and generator axes during power generation at the site. Preferably, the sub-base is mounted at an end adjacent the generator by the pair of clevis-type pivotal mounts spaced transversely one from the other as widely as possible along opposite sides of the trailer whereby the sub-base is pivotal at its aft end about those pivotal mounts. Because the isolator during transport permits limited vertical angular movement of the end of the turbine opposite the generator, the turbine rotor axis may angularly deflect relative to the generator axis upon over-road pivoting movement of the sub-base and turbine relative to the trailer and the generator. The pivotal mounts are also located at a like longitudinal location along the trailer as a flexible coupling between the turbine and generator rotors. This enables the turbine and generator axes to be maintained in approximate alignment with one another, notwithstanding angular deflection of the sub-base carrying the turbine about the transverse axis of the clevis-type mounts. Additionally, only a very slight lateral deflection of the sub-base mounting the turbine is permitted because of the pinned clevis-type connection between the sub-base and the base of the generator. The springs in the isolator maintain the end of the sub-base opposite the generator base in a central position limiting vertical and lateral deflections. 
     Not only is the initial alignment maintained during transport, minimizing the requirement for substantial alignment at the power generation site, but the foregoing described 3-point mounting also enables the torque of the turbine to be transferred directly from the turbine sub-base into the generator base rather than directly to the trailer. With this 3-point mounting, torque from the turbine is transferred through the pivot pins directly to the generator base. Preferably, the pivot mounts for the sub-base are located as wide apart as possible, given over-road transport requirements. This is significant because if the torque was transferred directly to the trailer, the turbine and generator axes would gradually and unpredictably move out of alignment. The trailer is not designed to absorb the torque of the turbine and, hence, in accordance with the present invention, the torque is transferred directly from the turbine to the generator base rather than directly to the trailer underlying the turbine. 
     In a preferred embodiment according to the present invention, there is provided a system for transporting a power generation unit comprising an elongated trailer mounted on a plurality of wheels on axles spaced from one another along the length of the trailer, an electromotive machine having a rotor rotatable about an axis and disposed on the trailer, the machine being secured to the trailer and being located with the rotor axis extending in a length direction of the trailer, a sub-base, a turbine having a rotor rotatable about an axis and fixed to the sub-base, the turbine and the electromotive machine being mounted on the sub-base and the trailer, respectively, with the rotor axes thereof in substantial axial alignment relative to one another, the sub-base adjacent an end thereof proximate the electromotive machine being connected to the trailer for pivotal movement about a transverse axis normal to the length direction of the trailer and a mounting between the trailer and the sub-base adjacent an opposite end of the sub-base remote from the electromotive machine limiting joint pivotal movement of the sub-base and an opposite end of the turbine from the electromotive machine about the transverse axis in a generally vertical direction whereby the axes of the rotors are maintained in approximate axial alignment relative to one another during transport of the power generation unit on the trailer. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side elevational view of a turbine and a generator mounted on a trailer configured for over-road transport in accordance with the present invention; 
     FIG. 2 is a perspective view of the power generation unit of FIG. 1 in a power generating mode on-site; 
     FIG. 3 is a side elevational view thereof; 
     FIG. 4 is a combined elevational and cross-sectional view of an isolator mounting for the forward end of the sub-base of the turbine; 
     FIG. 5 is a perspective view of a clevis forming a part of one of the two pivotal mountings of the sub-base for the turbine to the generator base; and 
     FIG. 6 is a partial side elevational and cross-sectional view of a flexible coupling between the rotors of the turbine and the machine. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to the drawings, particularly to FIG. 1, there is illustrated a power generation system, generally designated  10 , mounted on a trailer, generally designated  12 . The power generation system includes a turbine, e.g., a gas turbine  14 , and an electromotive machine  16 , e.g., a generator or alternator, both mounted on the trailer  12 . As illustrated, the trailer is elongated and has a pair of forward elongated support beams  18  and a pair of rear elongated support beams  19 , preferably welded to one another with the forward beams  18  at an elevation below the rear beams  19  for reasons which will become apparent. At the rear end of the trailer wheels  20  are mounted on three longitudinally spaced axles in a tandem alignment, preferably with air suspension. The forward end of the trailer is pinned to a removable trailer gooseneck  22  which, while not shown, is pivoted at its forward end to a trailer having multiple wheels and axles to which a tractor is pivotally secured. Mounted along opposite sides of the trailer at longitudinally spaced positions therealong are a plurality of independent landing legs  24 , preferably eight, with lower support and leveling plates  26 . The legs  24  can be lowered to support and stabilize the trailer as well as to elevate the wheels  20  from the ground as illustrated in FIG.  3 . 
     The generator is mounted directly on a base  28  (FIG. 1) which, in turn, is fixed to the rear beams  19  of the trailer  12 . Preferably, the base  28  of the generator  16  is welded to the rear beams  19 , rigidly fixing the generator to the trailer. 
     The turbine  14  is mounted on a sub-base  30  comprised of a structural framework. Various tie-downs  32  secure the turbine to the sub-base  30  at longitudinally spaced positions along the length of the turbine. The forward end of the turbine  14  is disposed in a shroud  34  having a central opening  36 , the shroud  34  being carried by sub-base  30 . Adjustable clevis-type mounts  38  interconnect the shroud  34  and the forward end of the turbine for supporting the turbine at its forward end. 
     In accordance with the present invention, the sub-base  30  is mounted to the trailer at three locations, i.e., a 3-point mount. Two pivotal connections  42  at the rear or aft end of the sub-base  30  pivotally mount the sub-base  30  to the base  28  of the generator which, in turn, is secured to the trailer. Alternatively, the rear end of the sub-base may be pivotally connected directly to the trailer. An isolator mount  40  secures the forward end of the sub-base  30  to the trailer along the centerline of the trailer. With reference to FIGS. 1 and 5, the two pivotal connections  42  joining the sub-base  30  to the base  28  of the generator preferably comprise clevis-type connections. For example, as illustrated in FIG. 5, the clevis-type connection  42  may comprise a base plate  44  and a pair of longitudinally projecting plates  46  spaced from one another and having openings  48  to receive pivot pins  50  (FIG.  1 ). The generator base  28  mounts a mating base plate  51  to which plate  44  is vertically adjustably secured. The rear end of sub-base  30  includes a base plate  52  having a rearwardly projecting support plate  54  for reception between the plates  46 . The plate  54  also includes an opening for receiving the pin  50  whereby the rear end of the sub-base  30  is pivotally coupled to the base  28  of generator  16  and, hence, to the trailer. The base plates  44  of the devises have vertically elongated openings  55  (FIG. 5) for securing the plates  44  to the base plates  51  of the generator base  28  at adjusted vertical positions to facilitate initial alignment of the rotor axes of the turbine  14  and generator  16 . 
     At the forward end of the sub-base  30 , the isolator mount  40  enables, during transport, limited displacement of the forward end of the sub-base  30  in a vertical direction, i.e., the sub-base pivots about the pivot pins  50 , necessarily requiring vertical movement of the forward end of the sub-base  30 . The isolator mount  40  is a commercially available mount having a movable support plate  60  secured to the sub-base  30  enabling movement of plate  60  in a limited vertical direction and biased for return to a neutral position by a plurality of springs  62 . The movable plate  60  is secured to the forward end of the sub-base  30  and hence the forward end of the turbine follows the movement of the plate  60 . Also, referring to FIG. 4, the base  64  of the isolator mount  40  is secured to the forward end of the trailer, e.g., the forward beams  18 , by suitable bolts, not shown, along a central longitudinal axis of the trailer bisecting the pivotal mounts  42 . The movable support plate  60  mounted on springs  62  thus moves vertically a limited distance under the bias of springs  62  relative to the base plate  64 . It will be appreciated that the movable plate  60  may be fixed in a vertically adjusted position to base plate  64  by suitable bolts when the power generation unit is set up to generate power at the site. Additionally, lateral movement of the support plate  60  relative to the base plate  64  is facilitated by springs  68 . Thus, to a very limited extent, the forward end of the sub-base  30  may be laterally displaced. It will be appreciated that during transport, the support plate  60  enables limited vertical and lateral movement of the forward end of the sub-base and that during start-up and power generating operations at the site, the isolator mount is locked down to the trailer, fixing the forward end of the sub-base  30  and hence turbine against either vertical or lateral movement. The lock-down is accomplished by bolting the movable plate  60  and the base plate  64  to one another such that the movable plate  64  cannot move, either vertically or laterally. 
     During transport and operation, a flexible-type, commercially available coupling  78  (FIG. 6) is provided between the turbine rotor  70  and the generator rotor  72 . The coupling  78  is available from Ameridrives International, Erie, Pa., and is identified as a Size # S22-G, Series: HH Ameriflex Coupling. Briefly, the coupling  78  includes a central sleeve  80  secured at opposite ends to flanges  82  and  84 . Flange  82  is secured to the interior diameter of a plurality of metal laminations  86 . The metal laminations  86  are secured at their outer diameter to a flange  88  which, in turn, is secured to the turbine rotor  70 . Similarly, at the opposite end of the coupling, the flange  84  is secured to the inner diameter of metal laminations  90 . The outer diameters of the laminations  90  are secured to a flange  92  forming part of a sleeve  94 , the opposite end of which has a flange  96  for securement to the generator rotor  72 . With this coupling, it will be appreciated that the axis of the turbine rotor may be angularly deflected relative to the axis of the generator rotor to a limited extent permitted by the laminations  86  and  90 . 
     In using the transport system hereof, the electromotive machine  16  is secured to the trailer  12  at a fabrication site. Particularly, the base  28  of the generator  16  is fixed, preferably by welding, to the support beams  19  of the trailer. The sub-base  30  is then pinned to the base  28  of the machine  16  by the clevis-type connections  42  and pins  50 . The forward end of the sub-base  30  is also secured to the movable support plate  60  of the isolator mount  40  previously secured to the forward end of the trailer to the beams  18 . With the turbine mounted on the sub-base, alignment of the axis of the turbine rotor  70  and machine rotor  72  is accomplished using standardized procedures. Note that the sub-base  30  may be adjusted vertically and shimmed laterally to align the rotor axes. The flexible coupling  78  may be applied to interconnect the rotors prior to transport or may be secured to the rotors at the power generation site subsequent to transport and during installation. 
     With the turbine and machine  16  mounted on the trailer as previously described, the trailer is transported to the power generating site. It will be appreciated that during such transportation, the trailer and, hence, turbine  14  and machine  16  are subjected to various road conditions which tend to misalign the axes of the rotors. For example, the trailer may sag and flex somewhat under the weight of the unit and the suspension systems may not be sufficient to avoid vibrating the turbine and machine tending to relatively displace the turbine and generator. The 3-point mounting of the sub-base  30  on which the turbine is mounted, however, maintains the rotor axes in substantial alignment throughout the transport and at the installation site. While the forward end of the turbine may be displaced vertically against the bias of the springs of the isolation mount  40  which is unlocked during transport (hence, the sub-base  30  pivots about the pins  50 ), the general alignment of the rotor axes is maintained. Consequently, only minimal adjustment of the turbine relative to the generator is necessary at the installation site. Moreover, upon start-up with the isolator mount locked down and during power generation, the torque generated by the turbine and transmitted to the sub-base  30  is, in turn, transmitted directly to the base of the generator  16  through the pinned connection. This avoids transfer of torque directly to the forward portion of the trailer and avoids applying stresses to the trailer which the trailer is not designed to accommodate. Because the isolator mount  40  is located along the centerline of the trailer, torque cannot be transmitted from forward end of the sub-base  30  to the trailer. By avoiding transmission of torque to the forward part of the trailer, the tendency of the turbine and generator to become misaligned during power generation is entirely avoided. 
     While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.