Device for cooling a motor in a climate control system

A conduit for providing air flow from an air conditioning housing to a motor for driving a climate control system air blower is disclosed. The blower is located in the air conditioning housing. The air conditioning motor includes a motor housing inlet port for admitting the air flow to the interior of the motor. The conduit comprises a generally cylindrical hose member having a motor housing end and a blower housing end. The blower housing end of the conduit extends through the blower housing wall and into the blower housing and defines a generally cylindrical wall. The generally cylindrical wall includes an angled portion and a stop wall portion opposite the angled portion which cooperate to guide air through the conduit to the motor.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention is directed to a device for cooling a blower motor 
used in a climate control system. More particularly, the invention is 
directed to a device for providing cooling air from an air conditioning 
plenum to the blower motor in the climate control system. 
2. Disclosure Information 
It is well-known that a stream of air from the passenger compartment of a 
motor vehicle may be drawn over a temperature sensor, to provide control 
of the temperature of air discharged into the passenger compartment by the 
vehicle's climate control system. This air typically is aspirated from the 
passenger compartment via a conduit connected either to the intake housing 
of the climate control system blower or to the suction housing of a 
separate small additional blower mounted behind the dashboard of the motor 
vehicle. U.S. Pat. No. 4,623,090 discloses a climate control system blower 
including a dual purpose fan, wherein air is aspirated from the passenger 
compartment of the motor vehicle by means of supplemental vanes attached 
to the backside of the impeller of the fan used to provide forced 
ventilation to the passenger compartment. This configuration, however, 
does not provide cooling for the blower motor. Without cooling, the motor 
could possibly become overheated, impairing its ability to function most 
efficiently. 
U.S. Pat. No. 5,364,025, assigned to the assignee of the present invention 
discloses a combination motor cooler and air aspirator which could be 
integrated with the blower motor of a motor vehicle climate control 
system. Such a device provides a tubular coupling from the interior of the 
passenger compartment to the motor and eliminates the need for a separate 
small additional blower. This system also provides cooling to the climate 
control system blower motor. 
Other proposals for providing cooling air to an air conditioning blower 
motor includes that described in U.S. Pat. No. 4,626,720. In the '720 
patent, a coupling extends between the air conditioning duct housing and 
the blower motor. A vacuum is created by the blower to draw air through 
the coupling to the motor. The arrangement shown in FIG. 1 of the '720 
patent illustrates that the coupling extends a small distance into the 
duct. Similar arrangements are shown in FIGS. 1A and 1B. In FIG. 1A, a 
tubular hose 12 extends through the plenum or duct sidewall 14 into an 
open area of the duct 16. Air flow is shown by arrows. In FIG. 1B, the 
hose 12 is flush with the sidewall 14. In both arrangements, very little 
air flows into the hose 12. This is because, in FIG. 1A, the air flow 
strikes the side of the hose 12 and creates a "dead zone" 18 or is forced 
over the hose, not into it. In FIG. 1B, the air flows over the top of the 
hose opening and because a vacuum is not created by the motor, the air is 
not drawn into the hose 12. Furthermore, the air flowing in FIG. 1B could 
create a venturi effect and draw air away from the motor, causing 
increased heating. 
Therefore, there is a need for a device which maximizes the amount of air 
flowing from the air conditioning plenum and through a hose into the 
motor. 
SUMMARY OF THE INVENTION 
It is an object of the present invention to provide a hose design which 
maximizes air flow to a blower motor of an air conditioning system. The 
present invention overcomes the disadvantages of the prior art by 
providing an apparatus for providing air flow to a motor which drives a 
climate control system air blower. The apparatus comprises a motor housing 
having an inlet port disposed in a wall thereof and a blower housing 
having an outlet port in a wall thereof. The apparatus further comprises a 
conduit for communicating air from the blower housing outlet port to the 
motor housing inlet port. The conduit includes a motor housing end and a 
blower housing end and a predetermined length of hose therebetween. The 
blower housing end of the conduit extends through the housing wall and 
into the blower housing and defines a generally cylindrical wall. The 
generally cylindrical conduit wall includes an angled portion and a stop 
wall portion opposite the angled portion. In one embodiment, the stop wall 
portion of the generally cylindrical wall extends approximately 180 
degrees around the circumference of the wall and the angled portion of the 
generally cylindrical wall extends approximately 180 degrees around the 
circumference of the wall. In another embodiment, the angled portion of 
the generally cylindrical wall includes an exterior angled portion and an 
interior angled portion, both extending at an angle of between three and 
45 degrees to the plane of the blower housing wall, but in converging 
relationship to one another. 
It is an advantage of the present invention that air flow to the motor from 
the blower hosing is increased, thus prolonging the life and efficiency of 
the blower motor. These and other objects, features and advantages of the 
present invention will become apparent from the drawings, detailed 
description and claims which follow.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Referring now to FIG. 2, there is shown generally at 20 a motor vehicle 
climate control system blower/ motor combination according to the present 
invention. The combination 20 comprises, inter alia, an aspirator blower 
wheel 22 and a discharge housing 24, although the present invention 
operates in climate control systems which do not such an aspirator blower 
wheel. The aspirator shown herein is merely shown an one example of 
components of an air conditioning system and is not a limitation upon the 
present invention. The aspirator blower wheel 22 and discharge housing 24 
are coupled to a motor vehicle climate control system air blower 26. The 
air blower 26 includes a permanent magnet-type direct current electric 
motor 28 which drives a conventional blower wheel 30. The motor 28 is 
mounted on a sidewall 32 of the blower housing (or plenum) and extends 
away from the blower housing as shown. The motor 28 includes a motor 
housing 34 and a shaft 36 extending through the housing 34. In known 
fashion, the aspirator blower wheel 22 is mounted onto the shaft 36 and 
the discharge housing 24 is secured to the motor housing 34 by means of 
conventional fasteners (not shown). 
A hose 40 extends between the sidewall 32 of the blower housing and the 
motor housing 34. The hose 40 provides cool air from the blower housing 44 
to the motor 28 to prevent the motor 28 from overheating. A motor engaging 
end 43 of the hose 40 extends though an inlet aperture 42 in motor housing 
34 in known fashion. The blower housing engaging end 46 of the hose 40 
extends through the sidewall 32 into the blower housing 44 as shown in 
FIGS. 3 and 3A. As shown therein, the blower end 46 of the hose 40 
includes a generally cylindrical wall having a groove 48 for receiving the 
sidewall 32 therein, a circumferential lip 50 extending into the blower 
housing and a stop wall 52 extending from the circumferential lip 50. The 
lip 50 has an exterior angled portion 54 which extends about half the 
circumference of the lip 50 and is disposed directly opposite from the 
stop wall 52. The lip 50 also includes an interior angled portion 56 with 
a generally flat area 55 between the exterior angled portion 54 and the 
interior angled portion 56. The interior angled portion 56 provides a 
ramped surface along which air flow from the plenum travels into the hose 
40. This interior angled portion 56 prevents a "dead zone" from forming at 
any portion of the lip 50 or hose 40. The stop wall 52 also extends about 
half the circumferential distance around the lip 50. 
In operation, and as shown in FIG. 4, the motor 28 rotates the climate 
control system blower wheel 30 to provide forced ventilation to the motor 
vehicle passenger compartment. As the air flows past the hose 40 in the 
blower housing 44, the air glides along the angled portion 54 of the 
circumferential lip 50, over flat portion 55 and some air begins traveling 
along interior angled surface 56 into hose 40. Another portion of the air 
flows over the aperture of the hose and is stopped at stop wall 52. From 
the stop wall 52, the air travels down into the hose 40 to the motor 28 
where the air circulates to prevent the motor from overheating. 
From the foregoing description, one ordinarily skilled in the art can 
easily ascertain the essential characteristics of the present invention, 
and without departing from the spirit and scope thereof, can make changes 
and modifications in the invention to adapt it to various usages and 
conditions. For example, as shown in FIG. 3, the hose 40 also includes a 
flexible connector 60 which can be used for holding wires or other 
conduits thereto. Also, the hose 40 can be made from various alternative 
elastomeric or polymeric materials. The angled portion 54 of lip 50 may 
extend from three to 45 degrees from the plane of the sidewall. Other 
means for providing air through the hose to the motor will be readily 
apparent to one ordinarily skilled in the art.