Patent Publication Number: US-2013243620-A1

Title: Dual outlet pump

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 61/389,776, filed on Oct. 5, 2010. The entire disclosure of the above application is incorporated herein by reference. 
    
    
     FIELD 
     The present disclosure generally relates to fluid pumps. More particularly, a pump having a first outlet providing a high fluid flow at low pressure and a second outlet providing low fluid flow at high pressure is described. 
     BACKGROUND 
     This section provides background information related to the present disclosure which is not necessarily prior art. 
     In typical present day automotive applications, manufacturers may utilize two separate fluid pumps associated with an automatic transmission. A first fluid pump provides a high fluid flow at a relatively low pressure to cool and lubricate the components of the automatic transmission. A second transmission fluid pump is configured to provide a high output pressure at a relatively low flow rate to control transmission operation. 
     More particularly, the high pressurized fluid is selectively placed in communication with one or more chambers such that a force may be applied to various clutches, brakes or other actuators to control transmission operation. While the separate pumps may have functioned satisfactorily in the past, it may be desirable to provide a pump including dual outlets providing the functions of both pumps in a single unit having a reduced size, cost and weight when compared to previous systems. 
     SUMMARY 
     This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features. 
     A dual outlet pressure pump includes a housing having first and second inlets as well as first and second outlets. A plurality of vanes are driven by a rotor. An asymmetric rotor cavity includes a first surface engaged by the vanes shaped to at least partially define a plurality of low pressure, high volume chambers. The cavity also includes a second surface engaged by the vanes shaped to at least partially define a plurality of high pressure, low volume chambers. Rotation of the rotor and vanes substantially simultaneously pumps a high volume of low pressure fluid between the first inlet and the first outlet and a low volume of high pressure fluid between the second inlet and the second outlet. 
     A fluid pump includes a housing having an inlet, a first outlet and a second outlet. A plurality of vanes are driven by a rotor rotatably supported in the housing. The vanes define pressure chambers having different volumes. The first and second outlets receive fluid from the inlet and are associated with chambers having a decreasing volume. The second outlet supplies fluid at a higher pressure and a lower flow rate than the first outlet. 
     Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. 
    
    
     
       DRAWINGS 
       The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure. 
         FIG. 1  is a perspective view of a dual outlet pump constructed in accordance with the teachings of the present disclosure; 
         FIG. 2  is a partial exploded perspective view of the pump shown in  FIG. 1 ; 
         FIG. 3  is a fragmentary view of a portion of the dual outlet pump; 
         FIG. 4  is a perspective view of a front plate of the dual outlet pump; 
         FIG. 5  is a rear view of the dual outlet pump; 
         FIGS. 6-9  are cross-sectional side views taken at different planes; 
         FIG. 10  is a cross-sectional side view of an alternate dual outlet pump; 
         FIG. 11  is a cross-sectional view taken through the pump depicted in  FIG. 10 ; 
         FIG. 12  is another cross-sectional view of the dual outlet pump taken at a different plane; 
         FIG. 13  is another cross-sectional view of the dual outlet pump taken at a different plane; 
         FIG. 14  is a cross-sectional side view of the dual outlet pump; 
         FIG. 15  is a perspective view of a rear plate; 
         FIG. 16  is another perspective view of the rear plate; 
         FIG. 17  is a perspective view of a front plate; 
         FIG. 18  is another perspective view of the front plate; 
         FIG. 19  is a perspective view of a mid-plate; 
         FIG. 20  is a fragmentary perspective view of another alternate dual outlet pump; and 
         FIG. 21  is a cross-sectional view of the dual outlet pump and motor assembly. 
     
    
    
     Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings. 
     DETAILED DESCRIPTION 
     Example embodiments will now be described more fully with reference to the accompanying drawings. 
       FIGS. 1-6  relate to a dual outlet pump  10  including a front plate  20 , a mid-plate  22  and a rear plate  24  fixed to one another by a plurality of threaded fasteners  26 . As shown in  FIG. 6 , fastener  26  is configured as a socket head shoulder bolt to assure a predetermined spacing between front plate  20  and rear plate  24 . A driveshaft  14  is fixed for rotation with a rotor  28  that rotates relative to front plate  20 , mid-plate  22  and rear plate  24 . Front plate  20 , mid-plate  22  and rear plate  24  are adapted to be positioned within a housing (not shown) having a cylindrical cavity. Rotation of driveshaft  14  causes a pumping of fluid from an inlet port  15  to a first outlet port  16 , as well as a second outlet port  18 . First outlet port  16  provides a high flow, low pressure output. Second outlet port  18  provides a low flow, high pressure output. 
     Pump  10  also includes a plurality of radially moveable vanes  32  positioned within a plurality of radially extending slots  34  formed in rotor  28 . A distal surface  36  of each vane  32  is in contact with an inner surface  38  of mid-plate  22 . Inner surface  38  is substantially cylindrically shaped having its center positioned at an eccentric location relative to a rotor axis of rotation  42 . Shaft  14  also rotates along axis of rotation  42 . The eccentric relationship between surface  38  and axis of rotation  42  defines a plurality of sequentially increasing and then decreasing chambers  46  between adjacent vanes  32 . First outlet port  16  is shaped and positioned to be in fluid communication with chambers  46  having a relatively large volume but decreasing in size such that a relatively high flow rate of pressurized fluid exits first outlet port  16 . Further along the circumference in the direction of decreasingly sized chambers, high pressure second outlet port  18  is positioned in communication with chambers  46  where a very minimal clearance exists between surface  38  of mid-plate  22  and an outer surface  50  of rotor  28 . The size of pressure chambers  46  at this circumferential location is relatively small thereby producing a relatively high pressure, low flow through second outlet port  18 . 
     A plurality of circumferentially spaced apart passageways  52  are provided in fluid communication with a proximal face  54  of each vane  32 . Passageways  52  are provided with pressurized fluid from one of low pressure outlet port  16  or high pressure outlet port  18 . Rear plate  24  includes a first groove  58  in communication with some of the passageways  52  and low pressure outlet port  16 . A passageway  59  interconnects groove  58  and first outlet port  16 . A second circumferentially extending groove  60  is in fluid communication with the remaining passageways  52  and high pressure outlet port  18 . A passageway  61  interconnects groove  60  and high pressure outlet port  18 . Front plate  20  also includes similar first and second grooves  64 ,  66 . Unlike typical vane pumps, the dual outlet pump  10  of the present disclosure is unbalanced due to a provision of high pressure and low pressure outlet ports. In an attempt to balance the loads through pump  10 , the circumferential extent of grooves  58 ,  64  is substantially greater than the circumferential extent of grooves  60 ,  66 . 
     Front plate  20  includes an inlet port groove  68  in fluid communication with inlet port  15  and several chambers  46  having sequentially increasing volumes. A similar inlet port groove  69  is provided on rear plate  24 . A low pressure outlet groove  70  circumferentially extends along a mating face  72  in communication with several chambers  46  having subsequently decreasing volumes. Rear plate  24  also includes a corresponding low pressure outlet groove  73 . A passageway  76  extends through front plate  20  exiting the side of the plate to provide low pressure fluid between a first o-ring  80  and a second o-ring  82 . A third o-ring  84  is positioned on rear plate  24 . O-rings  80 ,  82 ,  84  sealingly engage an inner cylindrical of the housing not depicted in the drawings. Low pressure fluid is provided between seals  80 ,  82  to enhance their sealing properties. 
     Front plate  20  also includes a high pressure outlet aperture  85  in fluid communication with second groove  66 . Mid-plate  22  includes a notch  90  for providing high pressure fluid in communication with second outlet port  18 . 
       FIGS. 10-19  depict a second dual outlet pump identified at reference numeral  200 . Pump  200  includes a housing  202 , a front plate  204 , a mid-plate  206 , and a rear plate  208 . Fasteners  210  interconnect front plate  204 , mid-plate  206  and rear plate  208 . Fasteners  207  fix a flange  209  of front plate  204  to housing  202 . A shaft  212  is fixed for rotation with a rotor  214 . A plurality of radially moveable vanes  216  are positioned within slots  218  formed in rotor  214 . Pressure chambers  215  are defined between adjacent vanes  216 , rotor  214  and mid-plate  206 . Driveshaft  212  rotates about an axis of rotation  217 . Bearings  219 ,  220  rotatably support driveshaft  212 . A lip seal  221  is positioned within front plate  204  and sealingly engages driveshaft  212 . 
     Housing  202  includes a low pressure inlet  222 , a high pressure inlet  224 , a low pressure outlet  226  and a high pressure outlet  228 . Mid-plate  206  includes an asymmetrical cavity  232  providing pump  200  with its dual output pressure characteristic. A first portion  236  of asymmetrical cavity  232  is defined by a first surface  238  and is spaced from an outer surface  240  of rotor  214  a maximum distance. As such, the volumes defined by pressurized chambers located between adjacent vanes  216  and first surface  238  are relatively large when compared to other pressurized chambers about the circumference of rotor  214 . More particularly, a second surface  246  defines a second portion  248  of asymmetric cavity  232 . Second surface  246  is positioned much closer to outer surface  240  of rotor  214  than first surface  238 . To provide pumping, it should be appreciated that both first surface  238  and second surface  246  are curved surfaces such that successive pressurized chambers of increasing volume and then decreasing volume are defined when the rotation direction of rotor  214  is taken into account. 
     As shown in the Figures, high pressure inlet  224  is associated with the increasing volume chambers at least partially defined by surface  246 . A high pressure inlet port  249  is formed in front plate  204 . A high pressure inlet port  250  is formed in rear plate  208 . The high pressure inlet ports  249 ,  250  are aligned with a high pressure inlet aperture  251  extending through mid-plate  206 . 
     High pressure outlet  228  is in fluid communication with the pressure chambers  215  having sequentially decreasing volumes at least partially defined by surface  246 . Pressurized fluid exits pressure chambers  215  through high pressure outlet ports  253 ,  255  in front plate  204  and rear plate  208 , respectively. A high pressure outlet aperture  257  interconnects high pressure outlet ports  253 ,  255 . 
     Low pressure inlet  222  is in fluid communication with a cavity  252  formed between an inner surface  254  of housing  202  and an outer surface  258  of mid-plate  206 . As shown in  FIGS. 14 and 19 , a chamfer  260  is formed on mid-plate  206  to provide a low pressure inlet passageway  261  for fluid passing through low pressure inlet  222  to enter the chambers at least partially defined by first surface  238 . Low pressure inlet ports  262 ,  264  are formed in front plate  204  and rear plate  208 , respectively. Low pressure inlet ports  262 ,  264  provide a reservoir and passageway for low pressure fluid to enter the chambers having sequentially increasing volume associated with first surface  238 . As rotor  214  rotates, pressurized fluid enters low pressure outlet ports  270 ,  272 . A low pressure outlet aperture  276  extends through mid-plate  206  and interconnects low pressure outlet ports  270 ,  272 . The high pressure fluid path remains separated from the low pressure fluid path. 
     Rotor  214  includes a plurality of passageways  292  positioned at the ends of slots  218 . Front plate  204  includes a first circumferentially extending slot  294  in communication with the low pressure fluid and an opposing circumferentially extending slot  296  in receipt of high pressure fluid. In similar fashion, rear plate  208  includes a first slot  300  in receipt of low pressure fluid and a second slot  302  in receipt of high pressure fluid. The size and shape of each of the slots corresponds to the positions of passageways  292  to apply pressurized fluid to a back face of vanes  216  to maintain engagement between each vane and first surface  238  and second surface  246 . 
       FIG. 20  depicts an alternate dual outlet pump  320 . Pump  320  is substantially similar to pump  200 . As such, like elements will retain their previously introduced reference numerals including a lower “a” suffix.  FIG. 20  represents a possible orientation of mid-plate  206   a  having low pressure inlet passageway  261   a  positioned on an opposite side of the pump as low pressure inlet  222   a.  It is contemplated that the pump  320  is mounted vertically as depicted in  FIG. 20 . The cavity  252   a  between outer surface  258   a  and inner surface  254   a  may become filled with fluid due to the position of pump  320  within a reservoir or some other fluid supply mechanism. The fluid to be pumped continues to fill cavity  252   a  until it reaches and enters low pressure inlet passageway  261   a.  As such, a particular customer&#39;s packaging requirements regarding the location of plumbing inlets and outlets may be met using this concept. 
       FIG. 21  represents an exemplary motor and pump assembly  350  including a motor  352  driving a shaft  354 . Shaft  354  is a monolithic, one-piece member extending through a mounting plate  356 . Shaft  354  is fixed for rotation with a rotor  358  of a pump  360 . Pump  360  may be configured as pump  10 , pump  200  or pump  320  without departing from the scope of the present disclosure. 
     The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.