Patent Publication Number: US-2022235754-A1

Title: Diaphragm pump drive for an electric pump

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
     This application claims the benefit of U.S. Provisional Application No. 62/856,354 filed Jun. 3, 2019, and entitled “DIAPHRAGM PUMP DRIVE,” the disclosure of which is hereby incorporated by reference in its entirety. 
    
    
     BACKGROUND 
     This disclosure relates generally to pumps. More particularly, this disclosure relates to pump drive systems. 
     Positive displacement pumps discharge a process fluid at a selected flow rate. In a typical positive displacement pump, a fluid displacement member, usually a piston or diaphragm, drives the process fluid through the pump. When the fluid displacement member is drawn in, a suction condition is created in the fluid flow path, which draws process fluid into a fluid cavity from the inlet manifold. The fluid displacement member then reverses direction and forces the process fluid out of the fluid cavity through the outlet manifold. 
     Displacement pumps include a drive system that powers the displacement member through the respective pumping and suction strokes. The drive system can be, pneumatic, hydraulic, or mechanical. For example, a pneumatic or hydraulic drive can route fluid to alternating chambers to cause reciprocation of the drive member. A mechanical drive converts a rotary output to a linear input to drive reciprocation. The mechanical drive can be powered electrically, pneumatically, or hydraulically and represents a relatively expensive component of the pump. 
     SUMMARY 
     According to one aspect of the disclosure, a displacement pump includes an electric drive having a drive housing defining a pump axis and a first fluid module mountable to an end of the drive housing. The first fluid module includes a first adaptor configured to interface with the drive housing, the first adaptor comprising a first inner mounting portion and a first outer mounting portion, wherein the first inner mounting portion interfaces with the drive housing at a first interface; a first cover configured to interface with the first outer mounting portion at a second interface; and a first diaphragm captured between the first adaptor and the first cover. A drive component of the electric drive disposed within the drive housing is accessible from outside of the drive housing through a central aperture of the first adaptor with the first adaptor interfacing with the drive housing. 
     According to an additional or alternative aspect of the disclosure, a displacement pump assembly includes an electric drive having a drive housing defining a pump axis; a first fluid module mountable to an end of the drive housing; and a second fluid module mountable to the end of the drive housing. The first fluid module includes a first adaptor configured to interface with the drive housing, the first adaptor comprising a first inner mounting portion and a first outer mounting portion, the first inner mounting portion configured to interface with the drive housing at a first interface; a first cover configured to interface with the first outer mounting portion at a second interface; and a first diaphragm captured between the first adaptor and the first cover. The second fluid module includes a the second fluid module including a second adaptor configured to interface with the drive housing at the first interface, a second cover that mounts to the second adaptor, and a second diaphragm captured between the second adaptor and the second cover. The second adaptor includes a second inner mounting portion and a second outer mounting portion, the second inner mounting portion configured to interface with the drive housing at the first interface. A first diameter of the first diaphragm is different than a second diameter of the second diaphragm. 
     According to another additional or alternative aspect of the disclosure, a method of servicing an electrically-powered displacement pump includes removing a first fluid cover from a first adaptor; and accessing, through the first adaptor, drive components disposed in a drive housing on which the first adaptor is mounted and within which at least one component configured to rotate about a motor axis is disposed. 
     According to yet another additional or alternative aspect of the disclosure, a displacement pump includes an electric drive having a drive housing defining a pump axis and a first fluid module mountable to an end of the drive housing. The first fluid module includes a first adaptor configured to interface with the drive housing, the first adaptor comprising a first inner mounting portion and a first outer mounting portion, a first cover configured to interface with the first outer mounting portion at a second interface, and a first diaphragm captured between the first adaptor and the first cover. The first inner mounting portion interfaces with the drive housing at a first interface. The first interface allows the first adaptor to be mounted at a plurality of adaptor mount positions. The second interface is a clocked interface that allows the first cover to be mounted at a single cover mount position. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  is an isometric view of an electrically operated pumping assembly. 
         FIG. 1B  is an exploded view of the electrically operated pumping assembly shown in  FIG. 1A . 
         FIG. 2  is a cross-sectional view taken along line  2 - 2  in  FIG. 1A . 
         FIG. 3A  is an isometric view of a second electrically operated pumping assembly. 
         FIG. 3B  is a cross-sectional view taken along line B-B in  FIG. 3A . 
         FIG. 4A  is an isometric view of an electrically operated pumping assembly with a first fluid module mounted. 
         FIG. 4B  is an isometric view of the electrically operated pumping assembly showing a first fluid manifold removed. 
         FIG. 4C  is an isometric view of the electrically operated pumping assembly showing the first fluid manifold and a first diaphragm removed. 
         FIG. 4D  is an isometric view of the electrically operated pumping assembly showing the first fluid manifold, the first diaphragm, and a first adaptor removed. 
         FIG. 4E  is an isometric view of the electrically operated pumping assembly showing a second fluid manifold, second diaphragm, and second adaptor removed. 
         FIG. 4F  is an isometric view of the electrically operated pumping assembly showing the second adaptor installed. 
         FIG. 4G  is an isometric view of the electrically operated pumping assembly showing the second adaptor and the second diaphragm installed. 
         FIG. 4H  is an isometric view of the electrically operated pumping assembly showing a second fluid module installed. 
         FIG. 5  is a cross-sectional view taken along line  5 - 5  in  FIG. 4H . 
         FIG. 6A  is an exploded isometric view showing an electrically operated pumping assembly with fluid modules removed and parts of a first drive exploded from the drive housing. 
         FIG. 6B  is an exploded isometric view showing the electrically operated pumping assembly with parts of the first drive removed. 
         FIG. 6C  is an exploded isometric view showing the electrically operated pumping assembly with parts of a second drive exploded from the drive housing. 
         FIG. 7A  is a rear elevation view of a second bearing shown in  FIG. 6C . 
         FIG. 7B  is a front elevation view of the second bearing plate shown in  FIG. 7A . 
         FIG. 7C  is a cross-sectional view taken along line C-C in  FIG. 7B . 
         FIG. 8  is a cross-sectional view of an electrically operated pumping assembly having the second bearing plates shown in  FIGS. 7A-7C . 
         FIG. 9A  is a front elevation view of an adaptor. 
         FIG. 9B  is a rear elevation view of the adaptor. 
         FIG. 9C  is a side elevation view of the adaptor. 
         FIG. 10A  is a side elevation view of an electrically operated pumping assembly with a fluid cover and diaphragm removed. 
         FIG. 10B  is an isometric view of the electrically operated pumping assembly showing removal of bearing plates through the adaptor. 
         FIG. 10C  is a side elevation view of the electrically operated pumping assembly with the adaptor removed. 
         FIG. 11  is a side elevation view of an electrically operated pumping assembly in a vertical orientation with the fluid cover and diaphragm removed. 
         FIG. 12A  is a side elevation view of an electrically operated pumping assembly showing a fluid cover in a misaligned position. 
         FIG. 12B  is an enlarged view of detail B in  FIG. 12A . 
         FIG. 13A  is a side elevation view of an electrically operated pumping assembly showing a fluid cover correctly aligned. 
         FIG. 13B  is an isometric view showing the electrically operated pumping assembly assembled in a vertical state. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1A  is an isometric view of pumping assembly  10 , which includes motor  12  and pump  14 .  FIG. 1B  is an exploded view of pump  14 .  FIGS. 1A and 1B  will be discussed together. Pump  14  includes inlet manifold  16 , outlet manifold  18 , drive housing  20 , fluid modules  22   a,  drive  24 , inlet check valves  26 , and outlet check valves  28 . Drive housing  20  includes body  30  having ends  32 . Each fluid module  22   a  includes fluid cover  34   a,  diaphragm  36   a,  and adaptor  38   a.  Each adaptor  38   a  includes inner mounting portion  40 , outer mounting portion  42   a,  and central aperture  44 . Drive  24  includes bearing plates  46   a  and rods  48 . 
     Pumping assembly  10  is configured to pump fluid from an upstream location to a downstream location. The fluid can be a liquid or a gas. Pump  14  pumps the fluid and motor  12  powers pump  14 . Motor  12  can be an electric motor configured to receive electrical energy, such as through a standard electrical outlet, and converts electrical energy to rotational output motion. For example, motor  12  can be a brushed or brushless DC motor, among other options. In some examples, a gearbox is disposed between motor  12  and drive  24 . The rotational output of motor  12  is converted into linear reciprocating motion by drive  24  to displace diaphragms  36   a  through respective pumping and suction strokes. 
     Pump  14  is connected to motor  12  and configured to be powered by motor  12 . Pump  14  includes inlet manifold  16  through which fluid is introduced to pump  14 . Pump  14  further includes outlet manifold  18  through which pumped fluid is output from pump  14 . Drive housing  20  is disposed between inlet manifold  16  and outlet manifold  18 . Drive housing  20  contains at least a portion of drive  24 . Drive housing  20  can be formed by one or more components. Drive housing  20  facilitates mounting of fluid modules  22 . Drive  24  is at least partially disposed within body  30  and is configured to covert the rotational output of motor  12  to a reciprocating linear input to power pump  14 . Drive  24  can be fully or partially contained within drive housing  20 . 
     Fluid modules  22   a  are mounted to ends  32  of drive housing  20 . Drive housing  20  is thereby disposed axially between fluid modules  22   a.  Pump  14  is shown as including dual fluid modules  22 . It is understood, however, that pump  14  can include a single fluid module  22  in some examples. Fluid modules  22   a  are disposed coaxially on pump axis P-P. 
     For each fluid module  22   a,  adaptor  38   a  is configured to mount to an end  32  of drive housing  20 . In some examples, adaptor  38   a  is in direct contact with drive housing  20 . Inner mounting portion  40  interfaces with drive housing  20 . Fasteners  50   a,  such as bolts, extend through inner mounting portion  40  and into drive housing  20  to secure adaptor  38   a  to drive housing  20 . As such, adaptor  38   a  mounts fluid module  22   a  to drive housing  20 . Fluid cover  34   a  is configured to mount to adaptor  38   a.  Fluid covers  34   a  define the axial ends of pump  14 . In some examples, fluid cover  34   a  is in direct contact with adaptor  38   a.  Outer mounting portion  42   a  interfaces with fluid cover  34   a.  Fasteners  50   b,  such as bolts, extend through fluid cover  34   a  and into adaptor  38   a  to secure fluid cover  34   a  to adaptor  38   a.  Diaphragm  36   a  is retained between adaptor  38   a  and fluid cover  34   a.  More specifically, diaphragm  36   a  is retained between and forms a seal between outer mounting portion  42   a  and fluid cover  34   a.  A pumping chamber  56  ( FIG. 2 ) is defined between diaphragm  36   a  and fluid cover  34   a.  The center of the diaphragm  36   a  is moved during a pump cycle while the peripheral edge of the diaphragm  36   a  is held in place between fluid cover  34   a  and adaptor  38   a  to increase and decrease the volume of the pumping chamber  56  to pump fluid. In the example shown, pump assembly  10  can be considered to be an electrically operated double diaphragm (EODD) pump. 
     Adaptors  38   a  extend between inner mounting portion  40  and outer mounting portion  42   a.  Inner mounting portion  40  has a first diameter and outer mounting portion  42   a  has a second diameter. The second diameter is larger than the first diameter such that adaptor  38   a  expands the diameter of fluid module  22   a  relative drive housing  20 . As such, the diameter of fluid module  22   a  expands from a smaller diameter facing drive housing  20  to a larger diameter facing away from drive housing  20 . 
     Inlet check valves  26  are disposed between inlet manifold  16  and fluid covers  34   a.  Outlet check valves  28  are disposed between outlet manifold  18  and fluid covers  34   a.  The flow of fluid being pumped is regulated by inlet check valves  26  and outlet check valves  28 . Inlet check valves  26  regulate flow into pumping chambers  56  and outlet check valves  28  regulate flow out of pumping chambers  56 . 
     Bearing plates  46   a  are disposed within drive housing  20 . Rods  48  extend between and connect the bearing plates  46   a.  Each bearing plate  46   a  is connected to a diaphragm  36   a  through central aperture  44  of adaptor  38   a.  In the example shown, bearing plates  46   a  are configured to provide the linear input to diaphragms  36   a  to drive reciprocation of diaphragms  36   a.  Rods  48  link bearing plates  46   a  together such that bearing plates  46   a  are linked for simultaneous reciprocation. 
       FIG. 2  is a cross-sectional view of pumping assembly  10  taken along line  2 - 2  in  FIG. 1A . Pumping assembly  10  includes motor  12  and pump  14 . Pump  14  includes inlet manifold  16 , outlet manifold  18 , drive housing  20 , fluid modules  22   a,  drive  24 , inlet check valves  26 , and outlet check valves  28 . Drive housing  20  includes body  30  and ends  32  and at least partially defines drive chamber  52 . Drive housing  20  further includes rod sleeves  54 . Each fluid module  22   a  includes fluid cover  34   a,  diaphragm  36   a,  adaptor  38   a,  and pumping chamber  56 . Each adaptor  38   a  includes inner mounting portion  40 , outer mounting portion  42   a,  and transition portion  58   a.  Diaphragms  36   a  include diaphragm plates  60 , membranes  62 , circumferential edge  64 , and connectors  66 . Drive  24   a  includes bearing plates  46   a,  rods  48 , eccentric  68 , and bearing  70 . Bearing plates  46   a  including mounting bores  72  and bearing surface  74 . 
     Motor  12  is connected to drive housing  20 . Drive  24  is at least partially disposed within drive chamber  52 . Motor  12  is configured to generate a rotational output and drive  24  is configured to convert that rotational output into a linear input to drive displacement of diaphragms  36   a  along pump axis P-P and cause pumping by pump  14 . 
     Bearing  70  is connected to eccentric  68  to be moved in a circular path offset from a central axis of rotation M of eccentric  68 . Bearing  70  is disposed between and interfaces with bearing plates  46   a,  which are also disposed in drive chamber  52 . More specifically, bearing  70  interfaces with bearing surface  74  of each bearing plate  46   a.  Rods  48  extend between and fix bearing plates  46   a  relative each other such that bearing plates  46   a  move simultaneously. In some examples, rods  48  have threaded ends that are connected to nuts on the outer axial sides of bearing plates  46   a.  Rods  48  extend through rod sleeves  54  formed in drive chamber  52 . In the example shown, rod sleeves  54  are formed by drive housing  20 . Rods  48  reciprocate within rod sleeves  54 . Rod sleeves  54  fix rods  48  to reciprocate axially along pump axis P-P. The bearing plates  46   a  and rods  48  form a carriage that moves linearly along pump axis P-P to move, via connectors  66 , the centers of the diaphragms  36   a  as driven by the eccentric  68  and bearing  70 . Bearing plates  46   a  are pushed by the bearing  70  axially, left and right. Bearing  70  does not push on anything as it moves vertically, thus the eccentric  68 , bearing  70 , and bearing plates  46   a  convert rotational motion into axial reciprocating motion which drives the diaphragms  36   a.    
     Fluid modules  22   a  are mounted to opposite axial ends  32  of drive housing  20 . A first one of fluid modules  22   a  is mounted to a first end  32  and a second one of fluid modules  22   a  is mounted to a second end  32 . Adaptors  38   a  are mounted to drive housing  20  and support the other components of fluid modules  22   a.  Inner mounting portion  40  is connected to drive housing  20  to secure fluid modules  22   a  to drive housing  20 . Fasteners  50   a  extend through inner mounting portion  40  into drive housing  20  to secure adaptors  38   a  to drive housing  20 . In the example shown, at least a portion of the fastener  50   a  is exposed within drive chamber  52 . 
     Inner mounting portion  40  interfaces with drive housing  20  at first interface  78 . Inner mounting portion  40  contacts drive housing  20  at first interface  78 . Inner mounting portion  40  seals with the end  32  of drive housing  20  with adaptor  38   a  mounted to drive housing  20 . In the example shown, annular seal  76  is disposed between drive housing  20  and inner mounting portion  40 . Annular seal  76  can be an o-ring, among other options. Annular seal  76  can be disposed in a notch formed in end  32  of drive housing  20 . It is understood that inner mounting portion  40  can include a groove or notch configured to receive annular seal  76 . The groove or notch in inner mounting portion  40  can be in addition to or replacement of the notch formed in drive housing  20 . 
     Fluid covers  34   a  are disposed between and fluidly connected to inlet manifold  16  and outlet manifold  18 . Fluid covers  34   a  are connected to outer mounting portions  42   a  of adaptors  38   a.  Fluid covers  34   a  contact outer mounting portion  42   a  at second interface  80 . Diaphragms  36   a  are captured between fluid covers  34   a  and adaptors  38   a.  More specifically, circumferential edge  64  is captured between adaptor  38   a  and fluid cover  34   a.  Circumferential edge  64  can include a bead disposed within grooves formed in outer mounting portion  42   a  and fluid cover  34   a.  Circumferential edge  64  forms an annular seal between fluid covers  34   a  and outer mounting portion  42   a.  In the example shown, complimentary grooves are formed on each of outer mounting portion  42   a  and fluid cover  34   a  to receive circumferential edge  64 . Diaphragms  36   a  seal between drive chamber  52  and pumping chamber  56 . The inner side of each diaphragm  36   a  is exposed to drive chamber  52  such that any fluid (e.g., air, hydraulic fluid, etc.) within drive chamber  52  can be in contact with either one of diaphragms  36   a.    
     Inner mounting portions  40  have a first diameter D 1  at first interface  78 . Outer mounting portions  42   a  have a second diameter D 2  at second interface  80 . The second diameter D 2  is larger than the first diameter D 1  such that adaptor  38   a  expands in diameter relative drive housing  20 . Transition portion  58   a  extends between and connects inner mounting portion  40  and outer mounting portion  42   a.  Transition portion  58   a  increases the diameter of adaptor  38   a  between inner mounting portion  40  and outer mounting portion  42   a.  The larger diameter of outer mounting portion  42   a  facilitates a larger diaphragm  36   a.  Diaphragm  36   a  has a diameter larger than a diameter of drive housing  20 . 
     Membrane  62  of diaphragm  36   a  is a flexible membrane. Diaphragm plates  60  interface with membrane  62 . Connectors  66  extend through an inner one of diaphragm plates  60  and extend at least partially through an outer one of diaphragm plates  60 . 
     Connectors  66  are disposed on axis P-P and are connected to bearing plates  46   a.  Connectors  66  extend into mounting bores  72  formed in bearing plates  46   a.  Connectors  66  fix bearing plates  46   a  to the centers of diaphragms  36   a.  Bearing plates  46   a  can thereby drive diaphragms  36   a  through each of the pressure stroke, during which the volume of pumping chamber  56  is reduced and fluid is driven through outlet check valve  28  from pumping chamber  56  to outlet manifold  18 , and the suction stroke, during which the volume of pumping chamber  56  is expanded and fluid is drawn through inlet check valve  26  to pumping chamber  56  from inlet manifold  16 . 
     Drive chamber  52  is defined axially between an inner (facing towards drive housing  20 ) side of each diaphragm  36   a.  Pumping chambers  56  are defined between the outer (facing away from drive housing  20 ) side of each diaphragm  36   a  and fluid covers  34   a.    
     During operation, motor  12  receives electric power and generates a rotational output. Drive  24  converts the rotational output of motor  12  to linear movement of diaphragms  36   a.  Drive  24  moves the centers of the diaphragms  36   a  back and forth in axial directions AD 1  and AD 2 , increasing and decreasing the volumes of pumping chambers  56 . Inlet check valves  26  and outlet check valves  28  regulate the flow of fluid through the pumping chambers  56  from an upstream to downstream direction. 
     The rotational output drives rotation of eccentric  68  about axis M. Bearing  70  rotates in a circular path about axis M. Bearing  70  interfaces with bearing surfaces  74  of bearing plates  46   a  and exerts a driving force on bearing plates  46   a.  Rods  48  link bearing plates  46   a  for simultaneous movement. For example, bearing  70  can move in a clockwise path from the position shown in  FIG. 2 . Bearing  70  exerts a driving force on the bearing plate  46   a  disposed on the right-hand side of bearing  70  (in the view of  FIG. 2 ) and pushes that bearing plate  46   a  in axial direction AD 1  to drive the diaphragm  36   a  associated with that bearing plate  46   a  through a pumping stroke. Rods  48  pull the other bearing plate  46   a  in axial direction AD 1  to pull the diaphragm  36   a  associated with that bearing plate  46   a  through a suction stroke. Diaphragms  36   a  are reciprocated on pump axis P-P through alternating pumping and suction strokes to pump the fluid. 
       FIG. 3A  is an isometric view of pumping system  10 ′, which includes motor  12 ′ and pump  14 .  FIG. 3B  is a cross-sectional view taken along line B-B in  FIG. 3A . Pumping system  10 ′ is substantially similar to pumping system  10  ( FIGS. 1A-2 ) except motor  12 ′ of pumping system  10 ′ is disposed within drive housing  20 . 
     Motor  12 ′ is disposed within drive housing  20  and is coaxial with pump axis P-P. Motor  12 ′ is disposed axially between fluid modules  22   a.  Motor  12 ′ is electrically powered and configured to drive diaphragms  36   a  in at least one of first axial direction AD 1  and second axial direction AD 2 . Drive  24  is disposed coaxially with motor  12 ′ on pump axis P-P. Drive  24  is connected to diaphragms  36   a  to drive diaphragms  36   a  linearly along pump axis P-P. 
     In some examples, motor  12 ′ is configured to generate a rotational output and drive  24  is configured to convert the rotational output to a linear input to displace diaphragms  36 . For example, motor  12 ′ can be a rotor/stator motor and drive  24  can receive the rotational output from the rotor, convert that rotational output to a linear input, and provide the linear input to diaphragms  36 . For example, drive  24  can include a ball screw or roller screw. The screw can be connected to the diaphragms  36  to displace diaphragms. The motor  12 ′ can be a reversible motor that rotates in a first rotational direction about pump axis P-P to cause diaphragms  36  to displace in one of first axial direction AD 1  and second axial direction AD 2  and rotates in a second, opposite rotational direction to cause diaphragms to displace in the other one of first axial direction AD 1  and second axial direction AD 2 . 
     In some examples, motor  12 ′ can be a solenoid configured to linearly displace drive  24 . For example, motor  12 ′ can be a double-acting solenoid configured to magnetically displace drive  24  in each of first axial direction AD 1  and second axial direction AD 2 . Drive  24  can be an armature including a permanent magnet. In other examples, motor  12 ′ can be a single-acting solenoid configured to magnetically displace drive  24  in one of first axial direction AD 1  and second axial direction AD 2 , while drive  24  is mechanically displaced in the other one of first axial direction AD 1  and second axial direction AD 2 . For example, a spring can displace drive  24  in the other one of the first axial direction AD 1  and the second axial direction AD 2 . 
     Fluid modules  22  can be utilized across a variety of pumps  14  having the same drive housing  20  but different motor configurations. Fluid modules  22  can thereby be changed between pumps  14  having different drive and motor configurations and/or components and can provide access to those configurations and components without requiring dismounting of adaptors  38 . 
       FIGS. 4A-4H  illustrate a sequence of removing fluid modules  22   a  from drive housing  20  and installing second fluid modules  22   b  on drive housing  20 . The removal of one of fluid modules  22   a  and replacement with one of second fluid modules  22   b  is discussed in detail. It is understood that the process is the same for removing the other one of fluid modules  22   a  and installing the other one of second fluid modules  22   b.  Fluid modules  22   a,    22   b  can be referred to collectively herein as “fluid modules  22 .” Both fluid modules  22  would typically be removed and replaced at the same time, in the same way.  FIGS. 4A-4D  show the process of removing fluid module  22   a.  It is understood that fluid module  22   a  can be installed in the reverse order of removal.  FIGS. 4E-4H  show the process of installing fluid module  22   b  on drive housing  20 . It is understood that fluid module  22   b  can be removed in the reverse order of installation. 
     In  FIG. 4A , pumping assembly  10  is shown with fluid modules  22   a  assembled to drive housing  20 . In  FIG. 4B , inlet manifold  16 , outlet manifold  18 , and fluid cover  34   a  are removed. Inlet manifold  16  and outlet manifold  18  are removed from fluid cover  34   a.  Fasteners, such as bolts, are released to remove inlet manifold  16  and outlet manifold  18 . Fluid cover  34   a  is detached from adaptor  38   a  by removing fasteners  50   b.    
     In  FIG. 4C , diaphragm  36   a  is detached from drive  24  and removed. The diaphragm  36   a  can be removed by release of the connector  66 , which may involve releasing parts of the connector  66  and/or diaphragm  36   a  which sandwich the center of the diaphragm  36   a.  For example, the connector  66  may be unthreaded from a diaphragm plate of the diaphragm  36   a.  In some examples, the diaphragm  36   a  can be rotated about pump axis P-P to disconnect diaphragm  36  from drive  24 , such as by unthreading the connector  66  from bearing plate  46 . With diaphragm  36   a  removed, fasteners  50   a  securing adaptor  38   a  to drive housing  20  are exposed. Components of drive  24  are also exposed through central aperture  44  of adaptor  38   a.  As discussed in more detail below, components of drive  24  can be accessed and serviced through central aperture  44  of adaptor  38   a.  In some examples of drive  24 , components of drive  24  can be removed through central aperture  44  while adaptor  38   a  remains mounted to drive housing  20 . 
     In  FIG. 4D , adaptor  38   a  is detached from and removed from drive housing  20 . Fasteners  50   a  are removed to release adaptor  38   a  from drive housing  20 . Fasteners  50   a  are removed from inner mounting portion  40  and drive housing  20 , disconnecting adaptor  38   a  from drive housing  20 . Fluid module  22   a  is thereby removed from pump  14 . 
       FIG. 4E  shows the introduction of fluid module  22   b.  Fluid module  22   b  is different than, but similar to, fluid module  22   a.  Fluid module  22   b  includes like components to fluid module  22   a  except components of fluid module  22   b  are larger than those of fluid module  22   a.    
       FIG. 4F  shows adaptor  38   b  mounted to drive housing  20 . Adaptor  38   b  includes inner mounting portion  40  and outer mounting portion  42   b.  Inner mounting portion  40  of adaptor  38   b  is configured to interface with and mount to drive housing  20  in the same manner as inner mounting portion  40  of adaptor  38   a.  Inner mounting portions  40  of each of adaptor  38   a  and adaptor  38   b  can have the same fastener opening configuration, the same diameters, and the same sealing faces. Adaptor  38   a  and adaptor  38   b  having inner mounting portions  40  of the same configuration facilitates mounting of the differently sized fluid module  22   a  and fluid module  22   b  to the same drive housing  20 . Adaptor  38   b  can be mounted to drive housing  20  by fasteners  50   a.    
       FIG. 4G  shows diaphragm  36   b  connected to drive  24  and disposed in place relative adaptor  38   b.  Diaphragm  36   b  of fluid module  22   b  has a larger diameter than diaphragm  36   a  of fluid module  22   a.  The larger size of diaphragm  36   b  facilitates pump  14  displacing a larger volume of fluid for each stroke. Diaphragm  36   b  is mounted to drive  24  in the same manner as diaphragm  36   a  and driven by drive  24  in the same manner as diaphragm  36   a.    
       FIG. 4H  shows fluid cover  34   b  mounted to adaptor  38   b  and inlet manifold  16  and outlet manifold  18  connected to fluid modules  22   b.  Fluid cover  34   b  is mounted to outer mounting portion  42   b  of adaptor  38   b.  Fluid cover  34   b  is placed over diaphragm  36   b  to capture diaphragm  36   b  between outer mounting portion  42   b  and fluid cover  34   b.  Fluid cover  34   b  can be mounted to outer mounting portion  42   b  by fasteners  50   b.  Outer mounting portion  42   b  has a larger diameter than outer mounting portion  42   a.  Fluid cover  34   b  has a larger diameter than fluid cover  34   a.  The larger diameters facilitate mounting of diaphragm  36   b  to cause the higher displacement per pump stroke. 
     Pumping assembly  10  provides significant advantages. Pumping assembly  10  has an electrically powered drive  24  that causes pumping by pump  14 . The drive  24  and motor  12  are relatively costly components of pumping assembly  10 . Pumping assembly  10  is modular and can be modified to output larger or smaller volumes of fluid per stroke. Each of fluid module  22   a  and fluid module  22   b  are configured to mount to drive housing  20 . Each of diaphragm  36   a  and diaphragm  36   b  connect to and can be displaced by drive  24 . Various fluid modules having different sizes and displacements can be mounted to the same drive housing  20  and powered by the same drive  24 . As such, the user can have a single motor  12 , drive  24 , and drive housing  20  and can modify pumping assembly  10  by mounting fluid modules  22  having any desired size to provide any desired displacement to the drive housing  20 . 
     The modular nature of pumping assembly  10  provides cost savings as the user is not required to purchase a different motor  12 , drive  24 , and drive housing  20  to obtain a different displacement and can instead mount different fluid modules  22 . The modular nature of pumping assembly  10  also provides a space savings as the user is not required to store full pump assemblies  10  and can instead simply store various fluid modules  22 , which require less storage space. The modular nature of pumping assembly  10  further provides for efficient changeover between pumps having various displacements. The other components of pumping assembly  10  can remain installed while the user swaps out fluid modules  22  to change the displacement of pump  14 . The user does not have to manipulate and remove the entire motor  12 , drive  24 , and/or drive housing  20 , providing savings in time and labor. 
       FIG. 5  is a cross-sectional view taken along line  5 - 5  in  FIG. 4H . Fluid modules  22   b  are mounted to drive housing  20 . Fluid modules  22   b  are disposed coaxially on pump axis P-P. 
     Inner mounting portion  40  interfaces with drive housing  20  at first interface  78 . Inner mounting portion  40  contacts end  32  of drive housing  20  at first interface  78 . Inner mounting portion  40  seals with the end  32  of drive housing  20  with adaptor  38   b  mounted to drive housing  20 . In the example shown, annular seal  76  is disposed between drive housing  20  and inner mounting portion  40 . Inner mounting portions  40  of adaptors  38   b  have diameters D 1  that are the same diameter as that of inner mounting portions  40  of adaptors  38   a.  The same diameters of inner mounting portion  40  of adaptor  38   b  and inner mounting portion  40  of adaptor  38   a  facilitates fluid module  22   b  mounting to the same drive housing  20 , in the same manner, and at the same location as fluid module  22   b.    
     Fluid covers  34   b  are disposed between and fluidly connected to inlet manifold  16  and outlet manifold  18 . Fluid covers  34   b  are connected to outer mounting portions  42   b  of adaptors  38   b.  Fluid covers  34   b  contact outer mounting portion  42  at third interface  82 . Diaphragms  36   b  are captured between fluid covers  34   b  and adaptors  38   b.  More specifically, circumferential edge  64  is captured between adaptor  38   b  and fluid cover  34   b.  Circumferential edge  64  can include a bead disposed within grooves formed in outer mounting portion  42   b  and fluid cover  34   b.  Circumferential edge  64  forms an annular seal between fluid cover  34   b  and outer mounting portion  42   b  at third interface  82 . In the example shown, complimentary grooves are formed on each of outer mounting portion  42   b  and fluid cover  34   b  to receive circumferential edge  64 . 
     Diaphragms  36   b  are connected to drive  24  and powered by drive  24  in the same manner as diaphragms  36   a.  Connectors  66  extend into mounting bores  72  formed in bearing plates  46   a  to fix bearing plates  46   a  to the centers of diaphragms  36   b.  Drive  24  can displace diaphragms  36  through each of the pressure stroke and the suction stroke. 
     Pumping assembly  10  with fluid modules  22   b  installed operates in the same manner as pumping assembly  10  with fluid modules  22   a  installed. Eccentric  68  rotates about axis M to drive bearing  70  in a circular path about axis M. Bearing  70  pushes on bearing plates  46   a  and rods  48  connect bearing plates  46   a  to simultaneously displace diaphragms  36   b  in one of the first axial direction AD 1  and second axial direction AD 2 . 
     Transition portion  58   b  extends between and connects inner mounting portion  40  and outer mounting portion  42   b.  Transition portion  58   b  increases the diameter of adaptor  38   b  between the diameter D 1  of inner mounting portion  40  and the diameter D 3  of outer mounting portion  42   b.  Diameter D 3  is larger than diameter D 2 . The larger diameter D 3  of outer mounting portion  42   b  relative to the diameter D 2  of outer mounting portion  42   a  facilitates use of the larger diaphragm  36   b  to generate higher flow. Diaphragm  36   b  has a diameter larger than a diameter of diaphragm  36   a.  The process discussed can also be utilized to mount a diaphragm having a smaller relative diameter to generate higher pressures and/or lower flow. 
     It is contemplated that a variety of sizes of fluid modules  22  can be connected to the same drive housing  20 . For example, ten different sizes having different diaphragm diameters can alternately be attached to the same drive housing  20  and driven by the same drive  24 . Each of the different sized fluid modules  22  is able to attach to the same end  32  of drive housing  20  at the same first interface  78  by the respective adaptor  38  of each fluid module  22  having the same fastener hole pattern and spacing to interface with the fastener holes of the drive housing  20 , yet each adaptor  38  can have a different size outer mounting portion  42  (e.g., different diameter) to accommodate the different sizes of diaphragms  36 . In this way, the adaptors  38  adapt between the single size of the first interface  78  with drive housing  20  and multiple different diaphragm configurations. 
       FIGS. 6A-6C  show a process of removing drive components configured to displace the diaphragms  36  through both pumping and suction strokes and replacing those drive components with drive components configured to displace diaphragms  36  through the suction stroke while working fluid within drive chamber  52  displaces the diaphragms  36  through a pumping stroke. 
     The drive  24  including bearing plates  46   a  is configured to drive the diaphragms  36  through both the suction and the pumping strokes. However, the pump  14  can be adapted so that the drive  24  moves the diaphragms  36  only through the suction strokes while the diaphragms  36  are then pneumatically or hydraulically pushed through the pumping strokes. The benefit of such a configuration is that the output pressure of the pump  14  will be at or near the pneumatic or hydraulic pressure that pushes on the diaphragms  36 , whereas only mechanical pushing through both the pumping and suction strokes can result in pressure spikes, particularly in deadhead conditions.  FIGS. 6A-6C  demonstrate the conversion of the drive  24 . 
     Each bearing plate  46   a  includes plate body  84 , mounting bore  72 , first receiving opening  86 , and second receiving opening  88 . Mounting bore  72  is formed in static projection  90 . Each bearing plate  46   b  includes plate body  84 , mounting bore  72 , first receiving opening  86 , and second receiving opening  88 . Mounting bore  72  is formed in pull  92 . Rods  48  include rod body  94  extending between contoured end  96  and cylindrical end  98 . 
     In  FIG. 6A , bearing plates  46   a  and rods  48  have been removed from drive housing  20 . Bearing plates  46   a  are shown in the inverse orientation relative each other. The bearing plate  46   a  to the left of drive housing  20  in the view of  FIG. 6A  is oriented such that first receiving opening  86  is at a lower end of plate body  84  and second receiving opening  88  is at a top end of plate body  84 . The bearing plate  46   a  to the right of drive housing  20  in the view of  FIG. 6A  is oriented such that first receiving opening  86  is at a top end of plate body  84  and second receiving opening  88  is at a lower end of plate body  84 . 
     Similar to bearing plates  46   a,  rods  48  are oriented inverse each other. The upper one of rods  48  shown is oriented with contoured end  96  facing in first axial direction AD 1  to be received by first receiving opening  86  of the bearing plate  46   a  spaced in first axial direction AD 1  from drive housing  20 . Cylindrical end  98  of the upper one of rods  48  is facing in second axial direction AD 2  to be received by second receiving opening  88  of the bearing plate  46   a  spaced in second axial direction AD 2  from drive housing  20 . The lower one of rods has contoured end  96  facing in second axial direction AD 2  and cylindrical end  98  facing in first axial direction AD 1 . 
     Contoured end  96  is configured to extend into first receiving opening  86 . Contoured ends  96  include a contour configured to mate with a contour of first receiving opening  86 . The mating contours prevent rod  48  from rotating relative bearing plate  46   a,    46   b.  For example, contoured ends  96  can include flats and first receiving openings  86  can be slots configured to mate with the flats. Contoured end  96  can be partially cylindrical and partially flat. In addition, the slot forming first receiving opening  86  can be vertically larger than contoured end  96 . The interface between contoured end  96  and first receiving opening  86  provides vertical play during assembly into drive housing  20  to allow rods  48  to properly mount within rod sleeves  54 . Cylindrical end  98  extends into second receiving opening  88 . Contoured end  96  and cylindrical end  98  have reduced diameters relative rod body  94 . 
     Extensions  100  project axially from each of contoured end  96  and cylindrical end  98 . With rods  48  interfacing with bearing plates  46   a,    46   b,  extensions  100  are disposed on opposite axial sides of plate body  84  from rod body  94 . Extensions  100  are removably connected to locks  102  to secure rods  48  to bearing plates  46   a.  In the example shown, extensions  100  are threaded shafts and locks  102  are nuts configured to threadingly engage mounting extensions. It is understood, however, that extensions  100  and locks  102  can interface in any manner suitable for securing rod  48  to bearing plate  46   a,    46   b.  Only one pair of locks  102  are shown, but it is understood that a pair of locks  102  is utilized to secure the pair of rods  48  to each bearing plate  46   a,    46   b.    
     During disassembly, locks  102  are removed from extensions  100  and bearing plates  46   a,    46   b  are pulled axially away from drive housing  20 . In some examples, the locks  102  associated with one of bearing plates  46   a,    46   b  are removed and then the rods  48  and other bearing plate  46   a,    46   b  can be removed while still assembled together. Rods  48  are disconnected from bearing plates  46 . 
     In  FIG. 6B , bearing plates  46   a  have been removed. In  FIG. 6C , bearing plates  46   b  are introduced. As discussed further below, bearing plates  46   b  have a different configuration than bearing plates  46   a.  Rods  48  are connected to bearing plates  46   b  and locked to bearing plates  46   b  by locks  102 . In some examples, contoured ends  96  are inserted into first receiving openings  86  and secured such that each bearing plate  46   b  has an associated rod  48  extending from it. Each bearing plate  46   b  and its rod  48  can then be inserted into drive housing  20  such that cylindrical ends  98  extend into second receiving openings  88  of the other bearing plate  46   b.    
     The carriage formed by bearing plates  46   a  and rods  48  or bearing plates  46   b  and rods  48  can be converted between different configurations within the same drive housing  20  and the different configurations are powered by the same motor  12 . Pumping assembly  10  provides significant advantages by facilitating the user switching between configurations by changing components of drive  24  without replacing the full pumping assembly  10 . 
       FIG. 7A  is a rear elevation view of bearing plate  46   b.    FIG. 7B  is a front elevation view of bearing plate  46   b.    FIG. 7C  is a cross-sectional view taken along line C-C in  FIG. 7B .  FIGS. 7A-7C  will be discussed together. Bearing plate  46   b  includes plate body  84 , mounting bore  72 , first receiving opening  86 , and second receiving opening  88 . Mounting bore  72  is formed in pull  92 . Pull  92  includes inner section  104  and outer section  106 . Plate body  84  defines pull chamber  108  and includes cover plate  110  enclosing pull chamber  108  and at least partially forming bearing surface  74 . 
     Pull  92  is at least partially disposed within pull chamber  108 . Inner section  104  includes an outwardly extending flange configured to mate with an inwardly extending flange to retain inner section  104  at least partially within pull chamber  108 . Outer section  106  includes an outwardly extending flange configured to mate with an inwardly extending flange to retain outer section  106  at least partially within inner section  104 . Inner section  104  and outer section  106  are each movable relative to plate body  84  and relative to each other. Mounting bore  72  is formed in outer section  106 . 
     Pull  92  is configured such that bearing plate  46   b  can exert a tensile pulling force on diaphragm  36  to pull diaphragm  36  through a suction stroke. Inner section  104  and outer section  106  form a series of telescopic parts that prevent bearing plate  46   b  from driving the diaphragm  36  through a pumping stroke. Pull  92  can collapse into pull chamber  108  to prevent bearing plate  46   b  from driving diaphragm  36  through a pumping stroke. 
       FIG. 8  is a cross-sectional view of pumping assembly  10  with drive  24 ′ including bearing plates  46   b  assembled within drive housing  20 . In this configuration, drive chamber  52  is pressurized with a working fluid to charge drive chamber  52 . For example, drive chamber  52  can be pressurized with compressed air or hydraulic fluid. Drive chamber  52  is fluidly sealed to prevent leakage of the working fluid from drive chamber  52 . A single charge of working fluid can provide pumping force over multiple pump cycles. The working fluid is not exhausted between pump cycles. The charge pressure of the working fluid corresponds to the pumping pressure output by pump  14 . 
     During operation, eccentric  68  causes bearing  70  to rotate about axis M to move the bearing plates  46   b  in a reciprocating manner in the first axial direction AD 1  and second axial direction AD 2 . Pull  92  is connected to connector  66  of diaphragm  36 . Pull  92  allows the bearing plate  46   b  to pull the connector  66  connected to outer section  106  toward the center of the drive housing  20 , corresponding to the suction stroke. As the bearing  70  reverses axial direction to push the bearing plate  46   b  through the pumping stroke, pull  92  can collapse in a telescopic manner within pull chamber  108 . Outer section  106  can collapse within inner section  104 . Both outer section  106  and inner section  104  can collapse within pull chamber  108 . Bearing plate  46   b  does not convey mechanical pumping force via the connector  66  to the diaphragm  36 . Instead, the working fluid within the drive chamber  52  pushes on the inner side of the diaphragm  36  to move the diaphragm  36  through the pumping stroke. While telescopic pull  92  is shown herein, other pull  92  options are possible, such as belts (e.g., chains, ropes, tendons, etc.) which can convey a pulling force but not a pushing force similar to the telescopic pull  92  shown. 
     Drive  24 ′ is configured to displace diaphragms  36  through respective suction strokes. Drive  24 ′ is prevented from displacing diaphragms  36  through respective pumping strokes by pulls  92  and bearing plates  46   b.  Instead, the working fluid charging drive chamber  52  is used to provide the force on the diaphragm  36  to drive diaphragm  36  through the pumping stroke. 
     As discussed with regard to  FIGS. 6A-8 , pumping assembly  10  can be converted from having a purely mechanical drive  24  to a hybrid drive  24 ′. The mechanical drive  24  mechanically displaces diaphragms  36  through each of the pumping stroke and the suction stroke. The hybrid drive  24 ′ mechanically displaces diaphragms  36  through the suction stroke and fluidically (e.g., pneumatically or hydraulically) displaces diaphragms  36  through the pumping stroke. The same drive housing  20  and motor  12  can be utilized with both the purely mechanical configuration and the hybrid configuration. The modular nature of pumping assembly  10  provides flexibility to the user, increases efficiency, and reduces costs. It is understood that hybrid drive  24 ′ can be utilized with any desired motor. For example, pulls  92  or other pulling options can be utilized with the arrangement shown in  FIG. 3B  where motor  12 ′ is fully within drive housing  20 . 
       FIG. 9A  is a rear elevation view of adaptor  38 .  FIG. 9B  is a front elevation view of adaptor  38 .  FIG. 9C  is a side elevation view of adaptor  38 .  FIGS. 9A-9C  will be discussed together. Adaptor  38  is substantially similar to adaptor  38   a  and adaptor  38   b.  Adaptor  38  includes inner mounting portion  40 , outer mounting portion  42 , central aperture  44 , and transition portion  58 . Inner mounting portion  40  includes inner ring  112  and outer mounting portion  42  includes outer ring  114 . Inner ring  112  includes voids  116 , projections  118 , and inner holes  120 . Outer ring  114  includes indicator  122  and outer holes  124 . Outer holes  124  include first subset  126  and second subset  128 . 
     Inner mounting portion  40  is disposed at a first end of transition portion  58  and outer mounting portion  42  is disposed at a second end of transition portion  58 . Transition portion  58  increases the diameter of adaptor  38  between the smaller diameter of inner mounting portion  40  and the larger diameter of outer mounting portion  42 . Central aperture  44  extends fully through adaptor  38 . 
     Inner ring  112  projects radially inward relative transition portion  58 . Inner ring  112  projects radially inward from a location where inner mounting portion  40  interfaces with and seals against end  32  of drive housing  20 . Voids  116  are disposed between projections  118 . Projections  118  are disposed between voids  116 . Inner holes  120  extend through projections  118  and are evenly arrayed about inner ring  112 . Inner holes  120  are disposed radially inward of the seal between inner mounting portion  40  and drive housing  20 . Inner holes  120  are evenly spaced about inner ring  112 . Inner holes  120  are symmetric about inner ring  112 . Inner holes  120  are configured to align with housing holes  130  ( FIG. 10C ) formed in end  32  of drive housing  20 . Fasteners, such as fasteners  50   a,  can extend through inner holes  120  and housing holes  130  to mount adaptor  38  to drive housing  20 . Inner holes  120  are evenly arrayed about inner ring  112  such that adaptor  38  can mount to drive housing  20  in any desired orientation. Any one of inner holes  120  can be aligned with any one of housing holes  130  to mount adaptor  38  to drive housing  20 . As such, adaptor  38  can be mounted at any desired clocked orientation relative to drive housing  20 . 
     Outer ring  114  projects radially outward relative transition portion  58 . Outer ring  114  projects radially outward from a location where outer mounting portion  42  interfaces with diaphragm  36  to form a seal between outer ring  114  and fluid cover  34 . Outer holes  124  extend through outer ring  114  and are configured to align with cover holes  132  ( FIGS. 12A-13A ) through fluid cover  34 . Outer holes  124  are disposed radially outward of the seal between outer mounting portion  42  and fluid cover  34 . Fasteners, such as fasteners  50   b,  can extend through aligned ones of outer holes  124  and cover holes  132  to mount fluid cover  34  to adaptor  38 . Unlike inner holes  120  that are evenly arrayed about inner ring  112 , outer holes  124  are not evenly arrayed about outer ring  114 . At least some of outer holes  124  have asymmetric spacing. First subset  126  of outer holes  124  have a first spacing therebetween and second subset  128  of outer holes  124  have a second spacing therebetween. The first spacing is different from the second spacing. In the example shown, the outer holes  124  forming first subset  126  are spaced closer together than the outer holes  124  forming second subset  128 . The difference in the spacing provides mistake-proofing that ensures fluid module  22  is properly aligned to pump fluid, as discussed further herein. The uneven spacing between outer holes  124  prevents fluid cover  34  from being mounted to adaptor  38  in an incorrect orientation. 
     Indicator  122  is disposed on outer ring  114 . In the example shown, indicator  122  is formed between second subset  128 . Indicator  122  is formed on a portion of outer ring  114  that is easily visible by the user with adaptor  38  installed on drive housing  20 . Indicator  122  shows the proper orientation of fluid cover  34  relative adaptor  38  to align outer holes  124  and cover holes  132  such that fluid cover  34  can mount to adaptor  38 . Indicator  122  can be of any desired form for informing the user of the proper orientation of adaptor  38 . For example, indicator  122  can be a bump, notch, gap, projection, symbol, difference in coloring, etc. suitable for indicating the proper orientation of adaptor  38 . 
       FIG. 10A  is a side elevation view of pumping assembly  10  showing components of drive  24  mounted within the drive housing  20  while adaptor  38  is mounted to drive housing  20 .  FIG. 10B  is an isometric view of pumping assembly  10  showing removal of bearing plate  46  through adaptor  38 .  FIG. 10C  is a side elevation view of pumping assembly  10  showing components of drive  24  mounted within drive housing  20  with adaptor  38  removed.  FIGS. 10A-10C  will be discussed together. 
     The ends of plate body  84  are aligned with voids  116  formed in inner ring  112  of adaptor  38 . Projections  118  in inner ring  112  support the material surrounding inner holes  120 , facilitating mounting of adaptor  38  to drive housing  20 . Voids  116  facilitate installation and removal of bearing plates  46  within drive housing  20  while adaptor  38  remains mounted to drive housing  20 . The ends of plate body  84  are aligned with voids  116  such that bearing plate  46  can be removed from drive housing  20  through voids  116  and central aperture  44 . Bearing plate  46  can thereby be removed from drive housing  20  while adaptor  38  remains installed on drive housing  20 . 
     As shown, the inner diameter of projections  118  generally would not allow (would block) the bearing plate  46  from being moved past inner ring  112  and out of drive housing  20 . The alignment of the ends of plate body  84  with voids  116  between projections  118  allows bearing plate  46  to be removed through adaptor  38  while adaptor  38  remains attached to drive housing  20 . 
     As seen in  FIG. 10B , bearing plate  46  has been moved axially outward from drive housing  20  past projections  118  while adaptor  38  remains mounted to drive housing  20 . The same or a different bearing plate  46  can be inserted into drive housing  20  through central aperture  44  and past projections  118 . Adaptor  38  allows for servicing of drive  24 , or for the exchange of different bearing plate  46  types (e.g. fully mechanical or partially mechanical and partially pneumatic/hydraulic as previously described) without removal of the adaptors  38 . Adaptor  38  allows for access to and servicing of various components of drive  24 . For example, components of motor  12 ′ ( FIG. 3B ) and its associated drive  24  are disposed fully within drive housing  20 . Such components can be accessed and serviced through adaptor  38  while adaptor  38  remains mounted. In some examples, a ball or roller screw forming such a drive  24  can be accessed through central aperture  44  and serviced. For example, such components can be lubricated through central aperture  44 . 
     Accessing drive  24  through central aperture  44  allows the connection between adaptor  38  and drive housing  20  to be maintained during servicing and/or replacement of components of drive  24 . Maintaining the connection between adaptor  38  and drive housing  20  while accessing components of drive  24  ensures that the annular seal (e.g., rubber O-ring) disposed at first interface  78  between inner mounting portion  40  and drive housing  20  is maintained. Maintaining first interface  78  ensures sealing of drive chamber  52  (e.g., of the pneumatic or hydraulic charge within the drive chamber  52 ) and it may be convenient to leave the annular seal in place during servicing, such that it is convenient to remove the bearing plates  46  for servicing and/or changing of configuration without removal of the adaptors  38 . 
     The drive housing  20  includes an extension that is shown orientated horizontally in  FIGS. 10-10C . For example, the extension can be a control housing for housing control components of an internally mounted motor or can be the motor and drive train for an externally mounted motor. In some cases, a user might want to change the orientation of the extension to orientate the extension in a more convenient way, such as to minimize the footprint of pump assembly  10  in a crowded facility. For example, the user may desire to orientate the extension vertically instead of horizontally. Either orientation is possible, but inlet check valves  26  and outlet check valves  28  are required to be orientated vertically because the check valves rely at least partially on gravity to transition to a closed state because springs are not used in this embodiment. 
     Housing holes  130  are evenly arrayed about end  32  of drive housing  20 . Housing holes  130  and inner holes  120  being evenly arrayed about pump axis P-P allows drive housing  20  to be oriented in any desired clocked orientation relative to gravity (eight orientations are possible in the example shown) while maintaining the check valves in the required vertical orientation. Due to the asymmetric pattern of outer holes  124  in the adaptor  38 , the adaptor  38  must be removed when the orientation of the drive housing  20  is changed. 
     The different spacing the first subset  126  of outer holes  124  and the second subset  128  of outer holes  124  ensures proper orientation of the inlet check valves  26  and outlet check valves  28  when pump  14  is assembled. The orientation of inlet check valves  26  and outlet check valves  28  follow the orientation of fluid covers  34 . As shown in  FIG. 10A , indicator  122  is a gap formed between second subset  128  of outer holes  124 . In such an example, indicator  122  and second subset  128  of outer holes  124  are intended to always be closest to the ground (relative to the direction of gravity), whereas first subset  126  of outer holes  124  is disposed furthest from the ground (relative to the direction of gravity). The relative position of indictor  122  and thus of first subset  126  and second subset  128  indicate proper orientation of adaptor  38  to ensure that fluid cover  34  is properly orientated. It is understood, however, that indicator  122  can be formed at any desired position on adaptor  38  to indicate the proper orientation of adaptor  38  relative to gravity. For example, indicator  122  can be disposed between first subset  126  of outer holes  124  such that indicator  122  is intended to always be furthest from the ground (relative to the direction of gravity), among other options. 
     Adaptors  38  including inner holes  120  having consistent spacing so that the adaptor  38  can be mounted to drive housing  20  in any clocked orientation. Adaptors  38  include outer holes  124  having inconsistent spacing so that fluid cover  34  can be mounted to adaptor  38  only in an orientation which properly orientates the inlet check valves  26  and outlet check valves  28 . It is expected that adaptor  38  will largely remain in place on drive housing  20  for an extended period (such as initial install by a technician likely to know how to orientate the adaptor  38  for proper fluid cover  34  alignment) while fluid cover  34  will be removed on a more frequent basis to access and service drive  24 . Any misalignment between fluid cover  34  and adaptor  38  when fluid cover  34  is reinstalled will be quickly discovered by the technician performing maintenance if adaptor  38  remains in place on drive housing  20  while fluid cover  34  is removed to perform the maintenance. Cover holes  132  (best seen in  FIGS. 12A-13A ) and outer holes  124  will be misaligned if fluid cover  34  is attempted to be installed in an incorrect orientation. Such misalignment prevents the insertion of fasteners  50   b  through cover holes  132  and outer holes  124  so fluid cover  34  cannot be mounted in an incorrect orientation relative adaptor  38 . So long as adaptor  38  remains attached during maintenance, then fluid cover  34  can only be properly connected to adaptor  38  in one orientation, which is the proper orientation. 
       FIG. 11  is an elevation view of pumping assembly  10  showing pumping assembly  10  in a vertical orientation.  FIG. 11  is substantially similar to  FIG. 10A  except drive housing  20  has been rotated 90-degrees counterclockwise such that the extension from drive housing  20  extends vertically above drive housing  20 . As discussed above, the even spacing between inner holes  120  facilitates mounting of adaptor  38  to drive housing  20  in any clocked orientation such that the extension from drive housing  20  extends in any desired direction. Adaptor  38  is mounted to drive housing  20  such that fluid cover  34  must be oriented vertically to ensure proper function of inlet check valves  26  and outlet check valves  28 . Indicator  122  is disposed at the bottom of pump assembly  10  and closest to ground relative the direction of gravity, ensuring that fluid cover  34 , and thus inlet check valves  26  and outlet check valves  28 , are in the proper orientation when pump  14  is fully assembled. 
       FIG. 12A  is an isometric view of pumping assembly  10  showing fluid cover  34  misaligned with adaptor  38  (best seen in  FIGS. 9A-9C ).  FIG. 12B  is an enlarged view of detail B in  FIG. 12A . Fluid cover  34  includes cover holes  132  that align with outer holes  124  when fluid cover  34  is properly oriented relative to adaptor  38 . Cover holes  132  include third subset  134  and fourth subset  136 . 
     Third subset  134  of cover holes  132  have a first spacing therebetween and fourth subset  136  of cover holes  132  have a second spacing therebetween. The first spacing is different from the second spacing. The difference in the spacing provides mistake-proofing that ensures fluid cover  34  is properly aligned with adaptor  38 . The uneven spacing between cover holes  132  prevents fluid cover  34  from being mounted to adaptor  38  in an incorrect orientation. 
     The spacing between third subset  134  of cover holes  132  and first subset  126  of outer holes  124  is the same. The spacing between fourth subset  136  of cover holes  132  and second subset  128  of outer holes  124  is the same. Such spacing ensures that third subset  134  of cover holes  132  interface with first subset  126  of outer holes  124  and that fourth subset  136  of cover holes  132  interface with second subset  128  of outer holes  124  when fluid cover  34  is mounted. Fluid cover  34  cannot be mounted to adaptor  38  except by aligning third subset  134  of cover holes  132  with first subset  126  of outer holes  124  and fourth subset  136  of cover holes  132  with second subset  128  of outer holes  124 . 
     Fluid cover  34  is shown as misaligned in  FIGS. 12A and 12B . Fluid cover  34  is shown in the orientation corresponding to the motor extension extending horizontally (as shown in  FIGS. 10A-10C ). As best seen in  FIG. 12B , the difference in hole pattern spacing results in a mismatch at hole  132   a  of fluid cover  34  such that there is no corresponding outer hole  124  aligned with hole  132   a.  The pathway through hole  132   a  is thereby blocked preventing the insertion of a fastener  50   b  through fluid cover  34  and adaptor  38  at that location. A portion of adaptor  38  is visible through hole  132   a,  which portion prevents the insertion of the fastener  50   b  through hole  132   a.  Fluid cover  34  cannot be fixed to adaptor  38  due to the misalignment. The inability to insert a fastener  50   b  provides a signal to the technician that fluid cover  34  is misaligned on adaptor  38 . Inlet manifold  16  and outlet manifold  18  are shown in their proper positions in  FIG. 12A , but it is understood that inlet manifold  16  and outlet manifold  18  are typically installed after fluid covers  34 , such that their positioning does not indicate the proper orientation of fluid cover  34  to the user. 
       FIG. 13A  is a side elevation view of pumping assembly  10  showing fluid cover  34  properly aligned on pumping assembly  10  and mounted to adaptor  38 .  FIG. 13B  is an isometric view of pumping assembly  10  with motor  12  oriented vertically. Fluid cover  34  is shown as correctly oriented such that all cover holes  132  are aligned with an outer hole  124  through adaptor  38 . Fasteners  50   b  can thereby be inserted through cover holes  132  and into outer holes  124  to fix fluid cover  34  to adaptor  38 . Inlet manifold  16  and outlet manifold  18  are mounted to fluid cover  34  and inlet check valves  26  and outlet check valves  28  are in the proper orientation relative gravity. 
     While the invention has been described with reference to an exemplary embodiment(s), it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment(s) disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.