Cooling Means For Motor Of A Wet Pick-up Vacuum Sweeper

Abstract

For use in a wet pick-up vacuum sweeper, a motor and fan assembly comprising a motor housing having ventilation openings for admitting cooling air, a motor disposed in the motor housing and having an output shaft extending from one end thereof, a fan element mounted on the shaft for rotation therewith to remove air from the canister of the vacuum sweeper, and a housing for the fan element connected to the said one end of the motor housing. The fan element housing provides a plurality of axially narrow, generally peripherally elongated exhaust ports spaced about its periphery and an entry port located generally concentrically with the shaft and providing communication between the fan element housing and the canister of the vacuum sweeper. One of the said housings provides wall means between the motor and fan element, this wall means having at least one exhaust opening providing communication between the housings so that rotation of the fan element draws cooling air through the motor housing and into the fan element housing to be expelled through its exhaust ports.

Description

It is an object of the present invention to provide, for use in a wet pick-up vacuum sweeper, a motor and fan assembly comprising a motor housing and a fan element housing with wall means therebetween formed to provide at least one exhaust opening providing communication between the housings. The provision of such exhaust openings in such wall means is an improvement over the prior art motor and fan assemblies for wet pick-up vacuum sweepers because it permits elimination of the usual separate cooling fan for the motor. Conventionally, motor and fan assemblies for vacuum sweepers which will pick up water are constructed in such a manner that the interior of the motor housing is sealed relative to the interior of the fan element housing. This conventional construction, of course, is intended to prevent the disasterous results obtained when water droplets get into the motor housing.

Thus, in conventional motor and fan assemblies for wet pick-up vacuum sweepers, a separate fan element is disposed on the shaft of the motor inside the motor housing to circulate air over the motor to keep it cool. This separate fan element necessarily occupies the space in the motor housing requiring the motor housing to be axially longer than it would have to be if the element were not required. Further, the cost of manufacturing the separate fan element and the cost of assembling it onto the motor shaft add to the overall cost of the motor and fan assembly.

The present invention eliminates the need for the separate fan element in the motor housing by providing a structure proportioned and designed such that operation of the fan element which removes air from the canister of the vacuum sweeper will also draw cooling air through the motor housing.

Other objects and features of the present invention will become apparent as this description progresses.

To the accomplishment of the above and related objects, the present invention may be embodied in the forms illustrated in the accompanying drawings, attention being called to the fact, however, that the drawings are illustrative only, and that change may be made in the specific constructions illustrated and described so long as the scope of the appended claims is not violated.

In the drawings:

FIG. 1 is a partially sectioned and cut away elevational view of a motor and fan assembly constructed in accordance with the present invention;

FIG. 2 is a fragmentary sectional view similar to FIG. 1 except that it shows a stator added to the fan element housing;

FIG. 3 is a fragmentary sectional view similar to FIG. 2 and showing, in addition to the stator shown in FIG. 2, tabs turned up from the fan element which draws air from the canister of the vacuum sweeper, the tabs being effective to increase the flow of air through the motor housing;

FIG. 4 is a fragmentary sectional view similar to FIG. 1 except that it shows a differently formed wall means separating the motor housing from the fan element housing; and

FIG. 5 is an elevation view, partially sectioned, of a different type of fan element constructed in accordance with the present invention.

Referring now to the drawings, and particularly to FIG. 1, it will be seen that there is illustrated a motor and fan assembly 10 including a motor housing 12 provided with ventilation openings 14 for admitting cooling air, a motor 16 disposed in the housing 12 and having an output shaft 18 extending from one end 20 of the housing, and a fan element housing 22 connected to the end 20 of the motor housing 12. The fan element housing 22 has an end or wall 24 facing the motor housing 12 and an opposite end 26, the fan element housing being axially relatively short as compared to its diameter. The housing 22 may be connected to the housing 12 by means such as the illustrated flange 28 and screw 30 arrangement. Particularly, the end 20 of the housing 12 in the illustrative embodiment is formed to provide a peripherally and radially outwardly extending flange 28 through which screws 30 extend threadedly to engage the end 24 of the housing 22.

In the illustration of FIG. 1, there is one large centrally located ventilation opening 14. This opening may be covered, for instance, with a perforated member or screen member providing a plurality of openings. Alternatively, the upper end of the housing 12 may be provided with a plurality of smaller perforations serving as ventilation openings. Thus, in this description and in the appended claims, the terms "ventilation opening" are intended to define one or more openings for admitting cooling air.

As illustrated, the housing 22 may be a two-part housing including the circularly formed part providing the end 24 and the circularly formed part providing the end 26 with fastening elements, such as the screws 32, connecting mating flanges of these two parts together.

The housing 22 is formed to provide a plurality of peripherally spaced apart, relatively axially short and peripherally elongated exhaust ports 34, and the opposite end 26 of the housing 22 is formed to provide an entry port 36 concentrically located relative to the axis of the shaft 18. The housing 22 is mounted on a vacuum sweeper such that the entry port 36 provides communication between the interior of the housing 22 and the canister portion of the vacuum sweeper. Such a general structural relationship is shown, for instance, in U. S. Pat. Nos. 3,082,465 issued Mar. 26, 1963 and 3,165,774 issued Jan. 19, 1965.

In the illustrative embodiment, the shaft 18 is journal mounted in a bearing 38 disposed in a seat 39 formed in the end 24 of the housing 22. Further, in the illustrative embodiment of FIG. 1, there are a plurality of exhaust openings 40 peripherally spaced apart about the seat 39 to provide communication between the motor housing 12 and the fan element housing 22, the openings 40 being in radially close proximity to the axis of the shaft 18.

A fan element 42 is mounted on the distal end of the shaft 18 for rotation therewith by means such as the illustrated nut 44 threaded on the shaft and spacer 46 disposed between the fan element and the inner race of the bearing 38. The illustrative fan element 42 includes first and second axially spaced apart, parallel and circular discs 48, 50, the disc 48 having a concentric opening 52 formed therein to be in registry with the entry port 36. A plurality of blade elements 54 are disposed between the discs 48, 50 and proportioned such that, when the fan element 42 rotates, air is drawn into the opening 52 to be expelled radially outwardly between the discs and through the exhaust ports 34. This particular type of fan element 42 is well known and need not be discussed, in detail, in this description.

It will be seen that the peripherally elongated exhaust ports 34 are disposed to be in radial registry with the space between the discs 48, 50 with the axial depth of the ports being approximately equal to the distance between the discs.

Thus, when the motor 16 is energized to drive the fan element 42, air is drawn through the entry port 36 into the opening 52 and then expelled radially outwardly through the ports 34 as indicated, for instance, by the dash lines 56. This movement of the air radially outwardly through the ports 34 causes movement of the air into the ventilation openings 14, about the motor 16, and then through the exhaust openings 40 and out through the ports 34 as indicated by the arrows 58. Particularly, the movement of the air radially outwardly through the ports as indicated by the arrows 56 provides an aspiration effect to decrease the pressure in the space between the disc 50 and the end wall 24. It has been discovered that this aspiration effect is effective to provide sufficient cooling air for the motor 16. It has also been found that water droplets carried in the air drawn through the openings 36, 52 and expelled radially outwardly through the ports 34 will not move upwardly and inwardly through the exhaust openings 40 into the motor housing 12.

Turning now to FIG. 2, it will be seen that there is illustrated a motor and fan assembly indicated generally by the reference numeral 66, the assembly including, in addition to the structure shown in FIG. 1, a stator 68 disposed axially between the fan element 42 and the wall 24. The stator 68 includes a circular member 70 disposed parallel and concentric with the discs 48, 50 and providing a concentric opening 71 through which the shaft 18 extends and a plurality of fins 72 extending radially outwardly and between the circular member 70 and the wall 24. The stator 68, which may be provided by a simple and inexpensive integrally molded plastic part fastened by conventional means to the wall 24, serves the purpose of directing the air moving through the exhaust openings 40 radially outwardly toward the exhaust ports 34, thereby to assist the aforementioned aspiration effect. The exhaust openings 40 may preferably be respectively located in the spaces between the peripherally spaced apart and radially extending fins 72.

Another function of the stator 68 is to prevent splashing of water droplets back up into the motor housing.

Turning now to FIG. 3, it will be seen that there is illustrated a motor and fan assembly indicated generally by the reference numeral 80 including, in addition to the structure shown in FIG. 2, a plurality of blades 82 carried by the second disc 50 and arranged to extend toward the wall 24. It will be appreciated that each of the blades 82 is disposed adjacent to and radially outwardly from the outer peripheral edge of the circular member 70 of the stator 68 and that each of the blades is inclined relative to a plane including the axis of the shaft 18 and extending radially outwardly therefrom. The purpose of the blades 82 is to draw air from the spaces between the fins 72 when the fan element 42 rotates. Particularly, the blades 82 assist the aspiration effect discussed in conjunction with FIG. 1 by providing a centrifugal pumping action.

The blades 82 may preferably be economically and conveniently provided by piercing the discs 50 at several points to provide tabs and turning the tabs upwardly to extend toward the wall 24.

Turning now to FIG. 4, it will be seen that there is illustrated a motor and fan assembly indicated generally by the reference numeral 86 which is similar to the structure of FIG. 1 except that the wall indicated at 24' is formed in a manner different from the flat wall 24 shown in FIG. 1. Particularly, the wall 24' is formed to provide a concentric portion 87 having an outer peripheral edge 88 and an inner peripheral edge 90, the portion inclining from its outer edge 88 to its inner edge 90 toward the fan element 42. The exhaust openings 40' are peripherally spaced apart in the inclined portion 87. The movement of the air radially outwardly as indicated by the arrows 56 draws the air from the housing 12 through the openings 40' as indicated by the arrows 58.

The systems shown in FIGS. 1-4 may be conventionally fabricated using sheet metal forming processes.

Turning now to FIG. 5, it will be seen that there is illustrated a motor and fan assembly indicated generally by the reference numeral 100, the housings for which and the fan element of which is fabricated by plastic molding techniques.

The assembly 100 includes a motor housing 102 which encloses a motor (only partially shown) including an output shaft 104 extending from the bottom end of the housing and journal mounted in a bearing 106. A fan element, indicated generally at 108, is mounted on the shaft 104 for rotation therewith, the fan element being disposed in an integrally formed housing 110 disposed at the lower end of the housing 102. The two housings, 102, 110, are formed such that there is a wall 112 disposed between the motor and the fan element 108, this wall 112 corresponding to the wall 24 discussed previously. Thus, the housing 110 includes an opposite end wall 114 corresponding to the opposite end wall 26 discussed previously, the wall 114 having a centrally located entry port 116. A plurality of peripherally spaced apart exhaust ports 118 are disposed about the periphery of the housing 110.

Communication between the motor housing 102 and fan element housing 110 is provided by the centrally located exhaust opening 120 formed in the wall 112. A foam ring 122 having a generally square cross section may be disposed in the opening 120 to prevent air recirculation. A similar ring (not shown) may be disposed in the opening 116.

The motor housing 102 and fan element housing 110 may be provided by forming two separate housing halves which mate together along a vertically extending plane which includes the axis of the shaft 104. The manner in which such a housing may be molded is well known and need not be discussed in further detail herein.

The fan element 108, in the illustrative embodiment, is integrally formed to include a hub portion 128, a peripherally and radially outwardly extending central flange portion 130, a plurality of peripherally spaced first blade elements 132 disposed on one side of the flange portion 130 to extend radially outwardly and toward the opposite end wall 114 and a plurality of second blade elements 134 disposed on the opposite side of the flange portion to extend radially outwardly and toward the wall 112.

In the illustrative embodiment, each second blade element 134 is formed to include a root portion 136 extending outwardly toward and terminating adjacent the outer peripheral edge of the exhaust opening 120 and particularly the ring 122 disposed in that opening. Further, each first blade element 132 is formed to include a root portion 138 extending outwardly toward and terminating adjacent the outer peripheral edge of the entry port 116.

As the fan element 108 rotates, the blade elements 132 draw air through the entry port 116 to expel the air radially outwardly as indicated by the arrows 140 while the blade elements 134 draw the air through the motor housing 102 and through the exhaust opening 120 to expel that air radially outwardly as indicated by the arrows 142. The blade elements 134, therefore, assist the aspiration effect of the movement of the air into the port 116 and radially outwardly through the exhaust ports 118.

Claims

What is claimed is:

1. For use in a wet pick-up vacuum sweeper, a motor and blower assembly comprising a motor housing having ventilation openings for admitting cooling air, a motor disposed in said motor housing and having an output shaft extending from one end thereof, a fan element mounted on said shaft for rotation therewith, and a housing for said fan element connected to the said one end of said motor housing, said fan element housing having an end facing said motor housing and having an opposite end facing away from said motor housing, said fan element housing providing a plurality of spaced apart exhaust ports about its periphery and an entry port located generally concentrically with said shaft and in its said opposite end, one of said housings providing wall means between said motor and said fan element, said shaft extending through said wall means, said wall means having at least one exhaust opening providing communication between said housings, and said fan element, fan element housing and wall means being proportioned and designed such that, when said fan element rotates to cause movement of air from said entry Port through said exhaust ports, cooling air for said motor moves into said ventilation openings and through said exhaust opening to be exhausted out through said exhaust ports.

2. The invention of claim 1 in which said fan element includes first and second axially spaced apart and circular discs with blade elements extending therebetween, said first disc being adjacent said opposite end and provided with a concentric opening registering with said entry port, and said exhaust ports being axially narrow and peripherally elongated and disposed to be in radial registry with the space between said discs.

3. The invention of claim 2 in which said wall means is generally parallel to said discs and in which there are a plurality of exhaust openings in said wall means located in radially close proximity to the axis of said shaft.

4. The invention of claim 3 including a stator disposed axially between said fan element and said wall means, said stator including a circular member disposed parallel and concentric with said discs and providing a concentric opening through which said shaft extends, and a plurality of fins extending radially outwardly and between said circular member and said wall means.

5. The invention of claim 4 including a plurality of blades carried by said second disc, each of said blades being disposed to extend toward said wall means.

6. The invention of claim 5 in which each of said blades is disposed adjacent to and radially outwardly from the outer peripheral edge of said circular member, each of said blades being inclined relative to a plane extending radially outwardly from the axis of said shaft to draw air from the spaces between said fins when said fan element rotates.

7. The invention of claim 6 in which each of said blades is provided by a tab pierced and turned out of said second disc to extend toward said wall means.

8. The invention of claim 2 including a plurality of blades carried by said second disc, each of said blades being disposed to extend toward said wall means.

9. The invention of claim 8 in which each of said blades is provided by a tab pierced and turned out of said second disc to extend toward said wall means and to be inclined relative to a plane extending radially outwardly from the axis of said shaft.

10. The invention of claim 1 including a stator disposed axially between said fan element and said wall means, said stator including a circular member disposed generally parallel with said wall means and providing a concentric opening through which said shaft extends, and a plurality of fins extending radially outwardly and between said circular members and said wall means, said wall means providing a plurality of said exhaust openings disposed radially inwardly from the outer peripheral edge of said circular member.

11. The invention of claim 10 in which said fan element includes first and second axially spaced apart and circular discs with blade elements extending therebetween, said first disc being adjacent said opposite end and provided with a concentric opening registering with said entry port, and said exhaust ports being axially narrow and peripherally elongated and disposed to be in radial registry with the space between said discs.

12. The invention of claim 2 in which said wall means is formed to provide a concentric portion having an outer peripheral edge and an inner peripheral edge, said portion inclining from said outer edge to said inner edge toward said fan element, said exhaust openings being peripherally spaced apart in said portion.

13. The invention of claim 1 in which said fan element includes a hub portion, a peripherally and radially outwardly extending central flange portion, a plurality of peripherally spaced first blade elements disposed on one side of said flange portion to extend radially outwardly and toward said opposite end, and a plurality of second blade elements disposed on the opposite side of said flange portion to extend radially outwardly and toward said wall means.

14. The invention of claim 13 in which said exhaust opening in said wall means is circular and disposed concentrically relative to said shaft, said second blade element being formed to include a root portion extending outwardly toward and terminating adjacent the outer peripheral edge of said exhaust opening, and each said first blade element being formed to include a root portion extending outwardly toward and terminating adjacent the outer peripheral edge of said entry port.