Abstract:
An improved cooling arrangement for an electric motor in a pump assembly, including a resilient fan baffle having a planar main surface and a pair of wings extending perpendicularly out from the main surface to direct airflow away from the motor when the fan baffle is installed on the motor. A method of installing the fan baffle includes bending two ends of the periphery of the fan baffle to clear obstructions on the motor, and then releasing the ends to allow them to come together in a planar arrangement.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
       [0001]    Reference is made to the following copending and commonly assigned U.S. patent applications by the same inventors, each of which was filed on the same day as the instant application, and each of which is hereby expressly incorporated by reference:  
         [0002]    i) STRAINER AND VALVE RELEASE, Ser. No. ______; and  
         [0003]    ii) IMPROVED SWASHPLATE PUMP, Ser. No. ______. 
     
    
     
       FIELD OF THE INVENTION  
         [0004]    This invention relates to the field of pumps for paint and related coating materials, more particularly, to electric motor driven pumps for such applications.  
         BACKGROUND OF THE INVENTION  
         [0005]    In the past, it has been known to provide sheet metal and other baffle plates and structures for directing air in electric motor driven equipment. Some baffle plates were commonly formed of one piece of planar material in the shape of a “C” and thus incompletely surrounded the parts they were adjacent to, and therefore incompletely directed air flow, or were of multiple pieces, requiring more parts and manipulation in assembly, with the consequent increase in cost and time to assemble, and potential for misassembly or incomplete assembly, where one or more pieces were omitted or incorrectly installed.  
           [0006]    The present invention overcomes shortcomings of the prior art by providing a single, three dimensional baffle plate having a main surface substantially completely surrounding the motor when installed, and having a pair of “wings” projecting from the main surface to direct cooling air to outlets in the paint pump apparatus. The fan baffle of the present invention is formed of resilient material and has a radial cut from the outer periphery to an aperture in the main surface, enabling the fan baffle to be temporarily flexed out of plane for installation, after which the main surface is restored to a planar condition with the aperture closely surrounding the motor to more effectively direct cooling air flow with respect to the motor. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0007]    [0007]FIG. 1 is a perspective view of a paint pump apparatus useful in the practice of the present invention.  
         [0008]    [0008]FIG. 2 is section view of the paint pump apparatus along line  2 - 2  of FIG. 1.  
         [0009]    [0009]FIG. 3 is a section view of the paint pump apparatus along line  3 - 3  of FIG. 2.  
         [0010]    [0010]FIG. 4 is a fragmentary section view along line  4 - 4  of FIG. 3.  
         [0011]    [0011]FIG. 5 is an exploded view of a portion of the paint pump assembly of FIG. 1 to illustrate the present invention.  
         [0012]    [0012]FIG. 6 is a view of the fan baffle of the present invention shown in a slightly deformed state preparatory to installation.  
         [0013]    [0013]FIG. 7 is a view of a fan baffle shown in the process of being installed on a motor assembly in the practice of the present invention.  
         [0014]    [0014]FIG. 8 is a simplified fragmentary diagram from the side illustrating installation of the fan baffle and showing certain details of a fan in the practice of the present invention.  
         [0015]    [0015]FIG. 9 is a view similar to that of FIG. 5, except with the fan baffle fully installed on the motor assembly.  
         [0016]    [0016]FIG. 10 is a front view of the fan baffle useful in the practice of the present invention.  
         [0017]    [0017]FIG. 11 is a side view of the fan baffle of FIG. 10.  
         [0018]    [0018]FIG. 12 is a top view of the fan baffle of FIG. 10.  
         [0019]    [0019]FIG. 13 is a bottom view of the fan baffle of FIG. 10.  
         [0020]    [0020]FIG. 14 is a rear view of the fan baffle of FIG. 10.  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0021]    Referring to the Figures, and most particularly to FIGS. 1 and 2, a paint pump apparatus  20  useful in the practice of the present invention may be seen. Apparatus  20  is intended to pump paint and similar coatings at high pressure to a spray gun (not shown) for application to a surface to be coated via airless spraying.  
         [0022]    Apparatus  20  includes a paint reservoir  22  and a pump assembly  24  carried by a frame  26 . Reservoir  22  may have a cover  28 . Frame  26  preferably has a handle portion  30  and a pair of foot portions  32 ,  34 . Foot portions  32  and  34  are received in a base  36  which supports pump assembly  24 . It is to be understood that a high pressure hose (not shown) is connected to an outlet  38  of the pump assembly  24  after a cap  40  is removed. The high pressure hose is also connected to an airless spray gun (not shown) for delivering paint or other coating material to a surface (not shown) desired to be coated. An inlet  42  of the pump assembly  24  is in fluid communication with reservoir  22 , and sealed against leakage therebetween by one or more O-rings  44 . It is to be understood that paint (or other similar coating material) is delivered by gravity from reservoir  22  to inlet  42  of the paint pump assembly  24 . As is conventional, a return tube  46  is provided from a pump and valve housing  48  containing inlet  42  and outlet  38 . Return tube  46  will return paint from the pump to the reservoir during a “priming” mode. A mechanical switch  50  enables transfer from the “priming” mode to a “run” mode wherein paint is delivered to the outlet  38  instead of the return tube  46 . An ON-OFF electrical switch (not shown) enables power from a power cord  54  (when connected to electrical supply, not shown) to be delivered to an electric motor (not shown). The motor or another form of prime mover, such as a gasoline engine (also not shown) provides mechanical power for pump assembly  24  which includes a piston  84  axially reciprocating in a cylinder or pumping chamber  119 . An inlet check valve  74  is positioned in inlet  42 . Similarly an outlet check valve  76  is positioned in outlet  38 .  
         [0023]    Referring now most particularly to FIG. 2, a gear box  58  couples motor  56  to a spider  60  which is journalled for rotation in pump assembly  24  by a bearing  62  and provides direct drive to a swashplate  64  via a shaft  66  on which the spider  60  and swashplate  64  are rigidly mounted. A distal end  68  of shaft  66  is journalled for rotation in a pump assembly housing  70  by a bushing  72 .  
         [0024]    An inlet check valve  74  is positioned in inlet  42 . Similarly an outlet check valve  76  is positioned in outlet  38 . A swashplate assembly  80 , which includes the spider  60 , bearing  62  and swashplate  64  are all mounted on shaft  66 . Assembly  80  also includes a rocker arm  82 , a piston  84 , a sleeve bearing  86 , and a seal  88 . In operation, swashplate  64  is rotated by motor  56  acting through gear box  58  and spider  60  when pump assembly  24  is to be operated, since swashplate  64  is carried on shaft  66 . Rocker arm  82  is constrained in a congruent cavity in pump and valve housing  48 , but is free to oscillate in a rocking motion when driven by rotation of swashplate  64 . Reciprocation of piston  84  will draw paint into a pumping chamber  119  through inlet  42  and deliver paint under pressure via outlet  83 .  
         [0025]    Referring now most particularly to FIGS. 3, 4,  5 ,  7  and  8  details of the outlet air flow from motor  56  may be seen. Cooling air flow passes through motor  56  in a conventional manner, and exits radially from motor  56  as indicated by arrows  170  as propelled by a radial fan  172  (see FIGS. 2 and 8). Air is directed by channels  174  integrally formed with a housing  176  for gearbox  58 , exiting via exhaust louvers  178 . It is to be understood that motor cooling air is drawn into the motor  56  via inlet louvers  180 .  
         [0026]    Referring now to FIGS. 5-14, a fan baffle  182  is located at a mounting position  184  with respect to motor  56 . Fan baffle  182  has a generally planar main surface  186  and preferably has a pair of wings  188  projecting from the main surface  186 , preferably perpendicularly. Main surface  186  defines a plane and substantially completely surrounds the motor  56  when baffle  182  is installed. Once the fan baffle is installed, the motor has a cooling air inlet located upstream of the fan baffle, and the fan  172  located downstream of the fan baffle for drawing cooling air axially through the motor  56 , because the main surface of the fan baffle closely interfits with the motor and main surface  186  and wings direct cooling air radially away from the motor and through the channels  174  toward exhaust louvers or outlet  178 . Fan baffle is preferably formed of VO rated polypropylene. The main surface  186  is preferably 0.060 inches thick, and the wings  188  are preferably 0.060 inches thick, and extend a distance of about 1 {fraction (1/16)} inches away from main surface  186 . It is to be understood that wings  188  in effect “complete” or extend channels  174 , by assisting in directing cooling air leaving the motor to be directed to louvers  178 . Only one wing is needed per side, because the motor  56  rotates in only one direction. Each wing is located on the downwind side of the channel with which it is associated. As may be seen most clearly in FIG. 4, if wing  188  were absent, air would be free to flow up into compartment  190  instead of being directed to louvers  178 .  
         [0027]    Fan baffle  182  has a centrally located aperture  192  sized and shaped to closely interfit with the motor  56  when the fan baffle is in the mounting position  184 . Fan baffle  182  also has an outer periphery  194  and a narrow slit  198  extending from the periphery  194  to the aperture  192 , forming separate ends  200  of the periphery of the fan baffle  182 . Wings  188  each preferably have a plurality of gussets  196  to provide structural rigidity and stability.  
         [0028]    The fan baffle  182  may be installed on the electric motor  56  by positioning the fan baffle adjacent an end of the motor, where the fan baffle is formed of a resilient material and has the aperture  192  in the fan baffle closely matching a first characteristic cross section  202  (FIG. 5) of the motor  56 , with the first characteristic cross section of the motor located at a mounting position  184  (FIG. 8) for the fan baffle  182 . The fan baffle is preferably moved over a first projection  204  of the motor by deforming the adjacent, but separate ends  200  of the periphery  194  of the fan baffle where the ends are formed by the narrow slit  198  in the fan baffle extending from the periphery of the fan baffle to the aperture, and moving the ends  200  of the periphery of the fan baffle past at least the first projection  204  on the motor having a characteristic cross section dimension greater than the first characteristic cross section  202  of the motor and releasing the ends  200  of the periphery of the fan baffle once they are moved past the first projection  204 . The installation of the fan baffle is completed by positioning the fan baffle  182  at the mounting position  184 . The first projection  204  is, in this case, a portion of a brush holder for the motor, but it is to be understood than any projection may be overcome with the method described above, while achieving a close interfit of the fan baffle with the motor upon installation.  
         [0029]    The method described above is particularly advantageous when the fan baffle has a generally planar main surface  186  and the method includes moving the ends  200  out of the plane of the main surface  186  In such case, the method further includes allowing the ends of the periphery to move to a position adjacent each other and generally in a plane of the main surface of the fan baffle upon installation of the fan baffle.  
         [0030]    The method of installation of the fan baffle is preferably performed by moving the fan baffle along the motor with the main surface  186  generally perpendicular to an axis  206  of the motor  56  until the fan baffle  182  is at the mounting position  184 .  
         [0031]    This invention is not to be taken as limited to all of the details thereof as modifications and variations thereof may be made without departing from the spirit or scope of the invention.