Abstract:
A retrofit kit for an Allison transmission for converting a standard Allison Transmission into a variable speed hybrid using external pressure. The retrofit kit for an Allison transmission includes a main housing; gear sets being disposed in the main housing and including rotational members; clutches being in operable communication to the gear sets; a hydrostatic pump being in operable communication to at least one of the rotational members and having ports; and a fluid circuit being in fluid communication to the hydrostatic pump through the ports and to at least one of the clutches.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to retrofit transmission kits and more particularly pertains to a new retrofit kit for an Allison transmission for converting a standard electronic automatic Allison transmission into a variable speed transmission by replacing the standard torque convertor, front pump, forward clutches and valve body with a variable speed torque convertor that is operated using external rather than internal pressure. 
     2. Description of the Prior Art 
     The use of retrofit transmission kits is known in the prior art. More specifically, retrofit transmission kits heretofore devised and utilized are known to consist basically of familiar, expected and obvious structural configurations, notwithstanding the myriad of designs encompassed by the crowded prior art which have been developed for the fulfillment of countless objectives and requirements. 
     The prior art includes torque converters and transmissions comprising a case or housing having input and output shafts being in operable communication to gear sets such as planetary carriers and planetary gears, sun gears and ring gears with standard clutches such as friction plates being used to couple the gear sets to manipulate the power to the output shaft which drive the drive wheel or wheels. While these devices fulfill their respective, particular objectives and requirements, the aforementioned patents do not disclose a new retrofit kit for an Allison transmission. 
     SUMMARY OF THE INVENTION 
     The general purpose of the present invention, which will be described subsequently in greater detail, is to provide a new retrofit kit for an Allison transmission which has many of the advantages of the retrofit transmission kits mentioned heretofore and many novel features that result in a new retrofit kit for an Allison transmission which is not anticipated, rendered obvious, suggested, or even implied by any of the prior art retrofit transmission kits, either alone or in any combination thereof. The present invention includes a main housing; gear sets being disposed in the main housing and including rotational members; clutches being in operable communication to the gear sets; a hydrostatic pump being in operable communication to at least one of the rotational members and having ports; and a fluid circuit being in fluid communication to the hydrostatic pump through the ports and to at least one of the clutches. None of the prior art includes the combination of the elements of the present invention. 
     There has thus been outlined, rather broadly, the more important features of the retrofit kit for an Allison transmission in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are additional features of the invention that will be described hereinafter and which will form the subject matter of the claims appended hereto. 
     In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting. 
     It is an object of the present invention to provide a new retrofit kit for an Allison transmission which has many of the advantages of the retrofit transmission kits mentioned heretofore and many novel features that result in a new retrofit kit for an Allison transmission which is not anticipated, rendered obvious, suggested, or even implied by any of the prior art retrofit transmission kits, either alone or in any combination thereof. 
     Still another object of the present invention is to provide a new retrofit kit for an Allison transmission for replacing the standard torque converter with a variable speed torque converter retrofit kit thereby changing the Allison transmission into a variable speed transmission using external pressure. 
     Still yet another object of the present invention is to provide a new retrofit kit for an Allison transmission that increases the fuel efficiency by a significant amount. 
     Even still another object of the present invention is to provide a new retrofit kit for an Allison transmission that replaces the standard torque convertor, front pump, forward clutches and valve body with a variable speed torque convertor that is operated using external rather than internal pressure. 
     These together with other objects of the invention, along with the various features of novelty which characterize the invention, are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and the specific objects attained by its uses, reference should be made to the accompanying drawings and descriptive matter in which there are illustrated preferred embodiments of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be better understood and objects other than those set forth above will become apparent when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawings wherein: 
         FIG. 1  is a cross-sectional side elevational view of a new retrofit kit for an Allison transmission according to the present invention. 
         FIG. 2  is a schematic diagram of the present invention. 
         FIG. 3  is a perspective view of the cone clutch and the clutch lockup member. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     With reference now to the drawings, and in particular to  FIGS. 1 through 3  thereof, a new retrofit kit for an Allison transmission embodying the principles and concepts of the present invention and generally designated by the reference numeral  10  will be described. 
     As best illustrated in  FIGS. 1 through 3 , the retrofit kit for an Allison transmission  10  generally comprises a main housing  11  having open ends, and also comprises planetary gear sets, a hydrostatic pump  36 , a first rotational member  12  in the form of a first shaft  12 , a second rotational member  13  in the form of a second shaft  13  and a hydraulic fluid circuit  50 . The first planetary gear set includes the three main components that correspond to the inputs/outputs; first planetary carrier  16  with a first set of planetary gears  17 , a sun gear  19 , and a ring gear  18 . The hydrostatic pump  36  through the hydraulic fluid circuit  50  may be used to control the rotation of one of the second shaft  13  and the third shaft  14 . 
     For purposes of illustration, the functionality will be described in the context of a vehicular application wherein a rotational power source is an input interconnected to the first rotational member  12  in the form of the first shaft. Furthermore, one or more drive wheels  60  are interconnected as an output to a fourth rotational member  15  in the form of a fourth shaft. The first shaft  12  is coupled to a first planetary carrier  16 , the third rotational member  14  is coupled to the sun gear  19  and the ring gear  18  is coupled to a second rotational member  13  for the hydrostatic pump  36 . If the ring gear  18  is held stationary, rotation of the first planetary carrier  16  will result in rotation of the sun gear  19 . If the first planetary carrier  16  is held stationary, rotation of the ring gear  18  will result in the rotation of the sun gear  19 . If any one of the three main components of the first planetary gear set is allowed to rotate freely, no rotational power may be transferred between the other 2 components. If no load is present on the ring gear  18  and a load is present on the sun gear  19 , rotational power delivered to the first planetary carrier  16  will result in rotation of the first planetary carrier  16  about the stationary sun gear  19  and ring gear  18  will rotate freely. 
     The third component of the first planetary gear set, the ring gear  18  is coupled to the hydrostatic pump  36 , an axial piston pump with reciprocating pistons  39   a,b . The ring gear  18  is interconnected to the second rotational member  13  in the form of a hollow shaft which is concentrically disposed relative to and disposed about the first shaft  12 . The hollow shaft is interconnected to a cylinder block  37 . Within a housing  49  is an angled swash plate  40  and the cylinder block  37 . Within the cylinder block  37  are a plurality of axial bores  38   a,b . A plurality of pistons  39   a,b  are slidably disposed in the bores  38   a,b . Each of the pistons  39   a,b  has a shoe  41   a,b  for slidably interfacing against the swash plate  40 . Hydraulic fluid passage  42  may be a single passage or a network of passages in fluid communication with a first port  44  on the hydrostatic pump  36 . Hydraulic fluid passage  43  may be a single passage in fluid communication with a second port  45  on the hydrostatic pump  36 . The pistons  39   a,b  ride along the swash plate  40  during rotation of the cylinder block  37 . They experience a compressive force for one half of each rotation of the cylinder block  37 . This compressive force corresponds to the rotation of the pistons  39   a,b . The hydraulic fluid passage  42  is in fluid communication with the first port  44 . The main case  11  contains hydraulic fluid passage  43  which is in fluid communication with the axial bores  38   a,b  and the second port  45 . All the axial bores  38   a,b  will rotate in and out of fluid communication with the hydraulic fluid passages  42 , 43 . As the pistons  39   a,b  undergo a compression stroke, the hydraulic fluid may be forced through hydraulic fluid passage  42  and the first port  44  may be the high pressure output port of the hydrostatic pump  36 . As the pistons  39   a,b  undergo an expansion stroke, the fluid may be drawn into hydraulic fluid passage  43  and second port  45  may be the relatively low pressure input port. To ensure that the pistons  39   a,b  undergoing an expansion stroke remain in continuous contact with the swash plate  40 , the hydraulic fluid circuit  50  may provide hydraulic fluid to the second port  45  under a pressure. This pressure may be supplied by a charge pump  65 . Minimum constant low pressure is held by the charge pump  65 . By selectively applying variable resistance to the third component, the ration between the rotation of the other 2 components can be continuously varied between the freewheeling mode and the locked mode. 
     A valve  46  interconnected to the first port  44  maybe operable to restrict flow of fluid from the first port  44 . The resistance of the hydrostatic pump  36  to rotation forces placed on the ring gear  18  can be continuously varied by regulating the output of the hydrostatic pump  36  through the valve  46 . If the valve  46  restricts the output of the hydrostatic pump  36 , this flow restriction may result in greater resistance to compression of the pistons  39   a,b  as they rotate. This resistance will translate into a resistance to the rotation of the ring gear  18  which in turn may cause power to be transmitted from the first shaft to the third shaft. By regulating flow through the valve  46 , the ration of the rotational rate of the first shaft with respect to the third shaft may be continuously varied. If the valve  46  used to restrict the output of the hydrostatic pump  36  is fully closed, no fluid may flow out of the hydrostatic pump  36 . Nearly 100% of the rotational power delivered to the first shaft  12  may be transmitted to the third shaft  14 . The first planetary gear set may function as a power dividing device if a load is applied to the ring gear  18 , a rotational input applied to the first planetary carrier  16  may be split between the sun gear  19  and the ring gear  18 . 
     The hydraulic fluid circuit  50  and the hydrostatic pump  36  may form a closed system where no external source of fluid is required and no fluid leaks from the system. The initial state of the vehicle drive train may be that the rotational power source is not providing rotational power, the valve  46  on the high pressure output side of the hydrostatic pump  36  is fully open, and the drive wheel  60  and hence the vehicle are locked in place by brakes of the vehicle. Since the valve  46  on the high pressure output side of the hydrostatic pump  36  is fully open, the ring gear  18  can rotate freely. Since the drive wheel  60  is locked by the brakes, the sun gear  19  will not rotate freely. When the power source  55  delivers rotational power, the first planetary carrier  16  will rotate the sun gear  19  while the ring gear  18  freewheels. At this point, a charge pump  65  is supplying pressure to the inlet/outlet ports  44 , 45  of the hydrostatic pump  36 . Initiate movement of the vehicle, the brakes of the vehicle drive train may be released, and the valve  46  may be incrementally closed or throttled to restrict flow through the first port  44 . The restriction of flow may result in a resistive torque being applied to the ring gear  18 , which may result in a torque being applied to the sun gear  19 . Once the resistive torque applied to the ring gear  18  meets or exceeds the resistive torque of the drive wheel  60 , the vehicle begins to move. As the valve  46  is further closed, more torque flows to the drive wheel  60  and the vehicle will accelerate. When the valve  46  is completely closed, all the torque generated by the power source  55  may flow through the first planetary carrier  16 , the sun gear  19  and the remainder of the drive train and to the drive wheel  60 . The axial piston pumps  36  may also function as hydrostatic motors. If high pressure fluid is delivered to the second port  45 , the fluid will impart an axial force on the pistons  39   a,b  which will cause the cylinder block  37  to rotate with the fluid passage  42  becoming the low pressure outlet. The hydrostatic pump  36  may be used as a starter motor by turning the ring gear  18  which in turn causes the first planetary carrier  16  to rotate thus rotating the crankshaft of the engine. Also, when the power source  60  is not running, the first planetary carrier  16  may be held stationary. High pressure fluid delivered to the hydrostatic motor may cause a torque being applied to the sun gear  19  and hence to the drive wheel  60 . Depending upon which port, either forward or reward motion of the vehicle may be achieved. 
     In addition, the retrofit kit for an Allison transmission  10  generally comprises clutches  22 , 25 , 26 , 30  being disposed in the main housing  11  and being in operable communication to the gear sets. The clutches  22 , 25 , 26 , 30  include a clutch lockup member  26  being conventionally engaged to the third rotational member  14  and to the sun gear  19 . The clutch lockup member  26  includes a plate member  27 , a boss portion extending outwardly from a side of the plate member  27 , a splined bore  28  being disposed through the boss portion and through the plate member  27  through which the third rotational member  14  is splined and rigidly connected to and also teeth being circumferentially spaced upon the side of the plate member  27 . The gear sets further include a second planetary carrier  20  being conventionally disposed in the main housing  11 . The clutches  22 , 25 , 26 , 30  also include a cone clutch  30  being conventionally engaged to the second planetary carrier  20 . The cone clutch  30  includes a plate member  31  having a bore  32  being disposed therethrough with the shaft portion of the second planetary carrier  20  being disposed and engaged in the bore  32  and further having teeth  32  being circumferentially spaced near and about the bore  32  on a side of the plate member  31 . The cone clutch  30  further includes a throw-out bearing  35  being in fluid communication to the fluid circuit  50  and also includes biased elements  34  such as springs being conventionally attached to the side of the plate member  31 . The fluid circuit  50  when conventionally actuated supplies fluid at a selected pressure to move the throw-out bearing  35 . Upon actuation of the fluid circuit  50  by conventional means, the teeth  29  of the clutch lockup member  26  are engaged to the teeth  33  of the cone clutch  30  upon fluid at a selected pressure from the fluid circuit  50  moving the cone clutch  30  relative to the clutch lockup member  26 . The gear sets also include a second set of planetary gears  21  being conventionally carried by the second planetary carrier  20  and being in operable and conventional communication to the fourth rotational member  15 . 
     Upon actuation of the fluid circuit  50 , fluid moves the cone clutch  30  into engagement to the clutch lockup member  26  with the cone clutch  30  being in operable communication to the second set of planetary gears  21  via the second planetary carrier  20  thus transmitting rotational power from the sun gear  19  and the second rotational member  14  to the second set of planetary gears  21  and to the fourth rotational member  15  and to the drive wheel  60  to propel the vehicle as such. The gear sets further include a third planetary carrier  23  being disposed in the main housing  11  and conventionally carrying a third set of planetary gears  24  and being in operable and conventional communication to the second set of planetary gears  21  via a first clutch assembly  22  such as friction plates which are in operable and conventional communication to the second set of planetary gears  21 . The third set of planetary gears  24  is in operable and conventional communication to the fourth rotational member  15  and to a second clutch assembly  25  such as friction plates. 
     Upon de-actuation of the fluid circuit  50  thus stopping the flow of fluid to the cone clutch  30 , the biased elements  34  move the cone clutch out of engagement to the clutch lockup member  26  thus resulting in power being transmitted from the third rotational member  14  to the fourth rotational member  15  or to the third set of planetary gears  24  and from the third set of planetary gears  24  to the fourth rotational member  15  via the second clutch assembly  25 . 
     As to a further discussion of the manner of usage and operation of the present invention, the same should be apparent from the above description. Accordingly, no further discussion relating to the manner of usage and operation will be provided. 
     With respect to the above description then, it is to be realized that the optimum dimensional relationships for the parts of the invention, to include variations in size, materials, shape, form, function and manner of operation, assembly and use, are deemed readily apparent and obvious to one skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention. 
     Therefore, the foregoing is considered as illustrative only of the principles of the retrofit kit for an Allison transmission. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.