Liquid pump assembly

An assembly for a liquid pump having inlet and outlet ports at its front side and an electric motor mounted on its operating shaft at its back side includes a one piece housing, preferably molded of a plastic. The housing includes a substantially flat top wall, a U-shaped bottom wall having the ends of its arms integral with the sides of the top wall, and a back wall integral with and extending across one end of the top wall and bottom wall with the other end of the housing being open. A mounting plate is secured to the pump between the pump and the motor. The pump and motor assembly is mounted in the open end of the housing with the motor being within the housing and the mounting plate being seated against the open end of the housing. Bolts extend through openings in lugs projecting from the arms of the bottom plate and are threaded into holes in lugs on the sides of the mounting plate to secure the mounting plate to the housing. Alignment pins project from the housing fits into alignment notches in the sides of the mounting plate to align the holes in the lugs on the housing and mounting plate. Wires from the motor extend through a notch in the mounting plate and cooperate with the edges of the notch to prevent longitudinal movement of the wires and thus provide a strain relief.

FIELD OF THE INVENTION 
The present invention relates to a liquid pump assembly, and, more 
particularly, to an improved housing for a pump and electric motor 
assembly. 
BACKGROUND OF THE INVENTION 
Many appliances, such as dish washers, clothes washers, etc., use a water 
pump which is driven by an electric motor. Most of these pump and electric 
motor assemblies are mounted in a single housing for ease of mounting in 
the appliance or the like. One type of housing which has been used for 
such an assembly included a flat metal top, a separate generally U-shaped 
metal bottom portion having the ends of its arms secured to the top, and a 
separate metal end plate secured across one end of the bottom portion and 
the top portion assembly. The end plate generally has a screen to allow 
air to enter the housing for cooling the motor. The pump and motor 
assembly is mounted and secured in the housing from its front open end. A 
problem with this type of assembly is that the housing is made of a number 
of different parts which must be assembled prior to inserting the pump and 
motor assembly therein. This is a time consuming operation which adds to 
the overall cost of the assembly. Therefore, it would be desirable to have 
a housing in which the pump and motor assembly can be easily and quickly 
assembled to lower the cost of the assembly. 
SUMMARY OF THE INVENTION 
An assembly of a pump and electric motor in which the pump has inlet and 
outlet ports at one side and a drive shaft extending from an opposite side 
to the motor is attached includes a one piece housing, preferably of a 
plastic. The housing has a substantially flat top, a substantially 
U-shaped bottom with its arms integral with and extending from opposite 
sides of the top, and a back wall extending across and integral with one 
end of the top and bottom with the other end of the housing being open. 
The pump and motor assembly is within the housing with the motor being 
adjacent the back wall and the inlet and outlet ports projecting from the 
open end of the housing. Means is provided for securing the pump and motor 
assembly in the housing. The one piece housing provides for greater ease 
of assembling the pump and motor assembly in the housing.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT 
Referring to FIGS. 1 and 2, the pump assembly of the present invention is 
generally designated as 10. Pump assembly 10 includes a one piece housing 
12, preferably molded of a plastic. The housing 12 includes a 
substantially flat top wall 14, a U-shaped bottom wall 16 having the ends 
of its arms integral with and extending from the sides of the top wall 14, 
and a back wall 18 integral with and extending across on end of the top 
and bottom walls 14 and 16. The back wall 18 closes one end of the housing 
12 leaving the other end 20 open. The back wall 18 has a series of 
ventilating openings 19 therethrough. A substantially cylindrical lug 22 
is integral with and extends longitudinally along the outer surface of 
each arm of the bottom wall from the open end 20 of the housing. Each lug 
2 has a hole 24 extending longitudinally therethrough. An alignment pin 26 
is integral with each arm of the bottom wall 16 above each of the lugs 22. 
The alignment pins 26 project beyond the open end 20 of the housing 12. A 
mounting arm 28 is integral with and projects upwardly from the top wall 
14. The mounting arm 28 has a pair of holes 30 therethrough by which it 
can be secured to a mounting bracket. A plate 32 is integral with and 
projects from the bottom wall 16 at the rounded portion thereof. The plate 
32 extends longitudinally along the bottom wall 16 and has a hole 34 
therethrough. As shown in FIG. 3, a semi-cylindrical shroud 35 is integral 
with and projects from the inner surface of the back wall 18. The shroud 
35 forms with the rounded bottom portion of the bottom wall 16 a 
cylindrical chamber. 
The housing 12 contains and supports an assembly 36 of a liquid pump 38 and 
an electric motor 40. The pump 38 is contained in a plastic housing 42 
having inlet and outlet ports 44 and 46 adjacent the front end thereof, 
and a shaft, not shown, projecting from the back end thereof. The electric 
motor 40 is at the back end of the pump 38 and is connected to the pump 
shaft so as to operate the pump. A metal mounting plate 48 is mounted on 
the back end of the pump housing 42 between the pump 38 and the electric 
motor 40. The mounting plate 48 is of a shape corresponding the 
cross-sectional shape of the housing 12 so that it can fit against the 
open end 20 of the housing 12. A pair of mounting lugs 50 having holes 52 
therethrough project from the sides of the mounting plate 48. The lugs 50 
are positioned so that they are aligned with the lugs 22 on the housing 12 
when the mounting plate 48 is seated against the open end 20 of the 
housing 12. The mounting plate 48 has a pair of alignment notches 54 in 
its sides above the mounting lugs 50. The notches 54 are positioned to 
receive the alignment pins 26 when the plate 48 is seated against the open 
end 20 of the housing 12. The mounting plate 48 has a large strain relief 
notch 56 in one side thereof adjacent it top edge. The wires 58 which are 
connected to the electric motor 40 to conduct current thereto, are encased 
in a metal casing 60 having a threaded exterior. The notch 56 is of a size 
to receive the casing 60 with the edges of the notch 5 fitting within the 
threads of the casing. Thus, when the casing 60 is within the notch 56 it 
is prevented from moving longitudinally so as to provide a strain relief 
for the wires 58. The mounting plate 48 has vent openings 55 therethrough 
to allow the flow of air through the housing 12. 
The pump and motor assembly 36 is mounted in the housing 14 by inserting 
the motor 40 into the open end 20 of the housing 14 until the mounting 
plate 48 is seated against the open end 20 of the housing 14. As the 
mounting plate 48 is moved close to the housing 14, the alignment pins 26 
fit into the alignment notch 54 in the sides of the mounting plate 48. 
This aligns the mounting plate 48 with respect to the open end 20 of the 
housing 14 and aligns the lugs 5 with regard to the ends of the mounting 
lugs 22 on the housing 14 so that the holes 24 in the mounting lugs 22 are 
aligned with the holes 52 in the lugs 50. In addition, the alignment pins 
26 hold the mounting plate 48 onto the end of the housing 1 while bolts 62 
are inserted through the holes 24 in the lugs 22 and threaded into the 
holes 52 in the lugs 50 to secure the mounting plate and assembly 36 in 
the housing 14. When the pump and motor assembly 36 is inserted into the 
housing 14, a fan 64 mounted on the back end of the motor 40 extends into 
and is supported in the chamber formed by the shroud 35 and the rounded 
portion of the bottom wall -6. The fan 64 serves to draw air into the 
housing 14 through the ventilating openings 19 in the back wall 18 to cool 
the motor 40. Thus, there is provided by the present invention a one piece 
housing 12 into which the pump and motor assembly 36 can be easily and 
quickly inserted and mounted with the motor 40 being in the housing 14 and 
the pump 38 being adjacent the open end 20 of the housing 14. When the 
assembly 36 is inserted in the housing 14 it is held in proper position by 
the alignment pins 26 fitting in the notches 54 in the mounting plate 48 
so that the assembler can easily secure the assembly 36 to the housing 14 
by means of the bolts 62. In addition, the wires 58 are secured against 
longitudinal movement by the metal casing 60 fitting in the notch 56 in 
the mounting plate 48 so as to prevent strain on the connection between 
the wires 58 and the terminals of the motor 40. The hole 34 in the plate 
32 is to allow a liquid exhaust tube to pass therethrough and hole the 
tube in position adjacent the assembly 10. The ease of assembling of the 
pump and motor assembly 36 in the housing 14 permitted by the present 
invention allows for a reduction in the cost of the assembly 10.