Title of Invention

"WATER DRAIN STRUCTURE OF FAN MOTOR"

Abstract A water drain structure of a fan motor having a cylinder-shaped housing (4) with a bottom and the opening thereof closed by an end lid (3), in which a rotor (1) and a stator (2) are accommodated therein; and a ring member (5) conforming to the outer circumference of the housing (4) and fitted on the outer circumference in the ring state so as to constitute a motor mounting portion and both side of the ring member (5) contact with housing (4) to guard water entering from that, wherein at a lowermost position of the housing (4) opposite to the ring member (5), a recess portion (8) having a rising wall surface (6) toward the inner surface side and a bottom surface (7) is provided, and a water discharge hole (9) is provided at the root or neighborhood of the rising wall surface (6), wherein a small chamber (10) is formed between the recess portion (8) and the ring member (5), and a water drain hole (11) is formed at the ring member (5) opposite to the center part of the bottom surface (7); characterized in that the recess portion (8) is formed in a trapezoidal shape having a height equal to or smaller than the height of the stator (2), and at least one pair of the water discharge holes (9) are provided at the root of the rising wall surface (6) located on both sides of the recess portion (8) in the axial direction of the housing (4). Figure 1
Full Text The present invention relates to water drain structure of fan motor.
Technical field
The present invention relates to a water drain structure of an electric fan motor of various vehicles.
Background Art
A radiator, a capacitor and the like of a vehicle are cooled by an electric fan motor in a standing state or a low-speed driving state. This fan motor needs to be protected from water attack such as splashed water or water thrown up by a tire. If water intrudes into the motor, it is necessary to drain the water rapidly to the outside.
A water drain structure of a fan motor is disclosed in Patent Document 1. In this fan motor, a lower end of a housing is divided by a permanent magnet as a stator into two parts in the axial direction, and a first water drain hole is formed at a front position at the lowermost part of the housing and a second water drain hole is provided downward in the neighborhood of an end lid of the housing. And a maze-state cover is attached to the second water drain hole.
[Patent Document 1] Japanese Patent No. 3168177
[Patent Document 2] Japanese Utility Model Publication-No. 7-24923
The above water drain structure requires machining for water drain at a front end and a rear end in the axial direction of a housing respectively, and attachment of a separate cover member at the rear end. This cover member might cost much since a material with high heat resistance is used in order to handle heat generation of an engine and the motor.
Also, if the cover member is broken/removed, there is a fear that water enters the inside of a casing which might promote insulation deterioration, corrosion or the like and lower durability of the fan motor.
Moreover, since separate parts covering the water drain hole are needed, that might raise the material cost and increase working time for assembling, and as a result, there is a problem that a price of the fan motor is raised.
The present invention has an object to solve the problems.
Disclosure of the Invention
The present invention described in Claim 1 is a water drain structure having a cylinder-shaped housing (4) with a bottom and the opening thereof closed by an end lid (3) , in which a rotor (1) andastator (2) are accommodated therein, and
aring member (5) conforming to the outer circumference of the housing (4) and fitted on the outer circumference in the ring state so as to constitute a motor mount ing portion,
wherein at a lowermost position of the housing (4) opposite to the ring member (5), a recess portion (8) having a rising wall surface (6) toward the inner surface side and a bottom surface (7) is provided, and a water discharge hole (9) is provided at the root or neighborhood of the rising wall surface (6);
a small chamber (10) is formed between the recess portion (8) and the ring member (5) , and a water drain hole (11) is formed at the ring member (5) opposite to the center part of the bottom surface (7).
The present invention described in Claim 2 is a water drain structure of a fan motor in Claim 1, wherein the recess portion (8) is formed in the trapezoidal shape having a height equal to or smaller than the height of the stator (2), and at least one pair of the water discharge holes (9) are provided at the root of the rising wall surface (6) located on both sides of the recess portion (8) in the axial direction of the housing (4) .
The present invention described in Claim 3 is a water drain structure of a fan motor in Claim 2, wherein on the outer surface side at the center part of the bottom surface (7), a water diffusion portion (12) is provided with the arc-state section projecting along the circumferential direction of the housing (4).
The present invention described in Claim 4 is a water drain structure of a fan motor in any one of Claims 1 to
3, wherein the stator (2) is made of a pair of arc-state
magnets (2a) , and a lower end edge of the respective magnet
(2a) is positioned on the rising wall surface (6) of the recess portion (8).
In the water drain structure of a fan motor of the present invention, the recess portion 8 is provided toward the inner surface side at the lowermost part of the housing
4, the water discharge hole 9 is provided at the root or
neighborhood of the rising wall surface 6, the small chamber
is formed between the recess portion 8 and the ring member
5, and the water drain hole 11 is formed at the ring member
5 opposite to the center part of the bottom surface 7.
By this construction, water having entered the housing 4 is discharged through the water discharge hole 9 at the root part of the recess portion 8, the small chamber 10, and the water drain hole 11 of the ring member 5.
Also, entering water 17 swiftly entering from the water drain hole 11 of the ring member 5 hits the bottom surface 7 of the recess portion 8, its momentum is weakened and is discharged to the water drain hole 11 from the upper face of the ring member 5 of the small chamber 10. On the other hand, water entered into the housing partially from the water discharge hole 9 is discharged to the outside from the water discharge hole 9 through the small chamber 10 and the water drain hole 11 again. Moreover, with this water drain structure, it is only necessary to add minor machining
operation to the conventional housing 4 and the ring member 5 and no additional parts are required. Thus, a simple water drain structure which hardly fails can be provided at a low cost.
In the above construction in which the recess portion 8 is formed in the trapezoidal shape and the water discharge holes 9 are provided at the root on the both sides of the recess portion 8 in the axial direction of the housing 4, water drain can be carried out rapidly, and even if the vehicle is located on a slope or the like and the fan motor is tilted, water drain can be made from either of the water discharge holes 9.
In the above construction, when a water diffusion portion 12 with the section in the arc state projecting along the circumferential direction of the housing 4 is provided on the outer surface side at the center portion of the bottom surface 7, the entering water 17 entering from the water drain hole 11 can be diffused by the water diffusion portion 12 in the circumferential direction so that the water is not moved to the water discharge hole 9 side located on both sides in the axial direction and the diffused water can be surely made to flow out to the outside from the water drain hole 11.
In any of the above constructions, when the stator 2 is made of a pair of arc-state magnets 2a and the lower edge of the respective magnets 2a is located on the rising
wall surface 6 of the recess portion 8, a positioning member at least at the lower end of the magnet 2a is not necessary any more, and a fan motor with a simple structure and fewer parts can be provided.
Brief Description of the Drawings
Fig. 1 is a partially cut-away front view of a fan motor having a water drain structure of the present invention.
Fig. 2 is a schematic sectional view on arrow II-II of Fig. 1.
Fig. 3 is an enlarged view of an essential part of the water drain structure of the present invention.
Fig. 4 is a perspective view on the inner surface side of a recess portion 8 provided in the water drain structure.
Fig. 5 is a schematic perspective view showing an example of a magnet holder 18 for positioning a pair of stators 2 of the fan motor of the present invention.
Best Mode for Carrying Out the Invention
An embodiment of the present invention will be described below based on the attached drawings.
Fig. 1 is a partially cut-away front view of a fan motor having a water drain structure of the present invention, Fig. 2 is a schematic sectional view on arrow II-II, and Fig. 3 is an enlarged view of the water drain structure in
Fig. 1. Fig. 4 is a schematic perspective view of a recess portion 8 seen from the inner surface side of the housing 4.
The fan motor has the housing 4 formed in the cylindrical shape with a bottom and an end lid 3 for closing its one-end opening. In the housing 4, a stator 2 made of a pair of magnets 2a and a rotor 1 are attached. To the rotor 1, an output shaft 14 shown in Fig. 1 is fixed at its center, and the both ends are supported by a bearing 13 of the end lid 3 and the bearing 13 provided at the bottomportion of the housing 4 with one end of the output shaft 14 protruding in the axial direction. And a fan, not shown, is attached to this output shaft 14.
On the outer circumference of the housing 4, a ring-state ring member 5 conforming thereto is fitted, and both are integrally fixed by means such as welding. At one end edge of the ring member 5 in the axial direction, flange portions 16 are projected in the direction perpendicular to the axis with 120° separated from each other. A bolt hole is drilled in the flange portion 16, and by using a bolt inserted through the hole and a fan shroud stay, the fan motor is integrally mounted on the axis of the fan shroud. At the housing 4, a recess portion 8 is provided at its lowermost position toward the inner surface side.
This recess portion 8 is, as shown in Fig. 4, formed with the lateral section in the trapezoidal shape and has
a bottom surface 7 whose peripheral edge portion becomes a rising wall surface 6. At the center part in the circumferential direction of the bottom surface 7, a water diffusion portion 12 with the arc-state section projecting is provided on the outer surface side. The width of the recess portion 8 of the housing 4 in the axial direction (hereinafter referred to simply as the axial direction) is substantially equal to the width of a laminated steel plate of the rotor 1 in the axial direction, and also is substantially equal to the width of the magnet 2a of the stator 2. At the root of both the rising portions 6 in the axial direction, a pair of water discharge holes 9 is drilled. The lower end edge of each of the pair of magnets 2a is brought into contact with both the rising wall surfaces 6 in the circumferential direction of the recess portion 8 . In a space between the upper end edges of both the magnets 2a, a magnet holder 18 is pressed in (Fig. 2). By this, the pair of magnets 2a is positioned and fixed on the inner surface of the housing 4. This magnet holder 18 is formed in a U-shape as shown in Fig. 5 as an example and made of a material which can be elastically deformed in a direction where the opening of the U-shape can be expanded or contracted. On the outer surface side of the recess portion 8 of the housing 4, the ring member 5 is fitted. The ring member 5 has a water drain hole 11 drilled opposite to the center of the bottom surface 7 of the recess portion 8.
(Performance)
In rainy weather, when the fan motor is attacked with water such as splashed water or water thrown up by a tire of a vehicle, entering water 17 enters a small chamber 10 in the fountain state as shown in Fig. 3. Then, this entering water 17 hits the bottom surface 7 of the recess portion 8 and is diffused in the circumferential direction by the water diffusion portion 12 . Then, its momentum is weakened and the water drops onto the upper surface of the ring member 5 in the small chamber 10 and most of the water drops downward from the water drain hole 11. A part of the water enters the housing 4 from the water discharge hole 9 but is immediately returned to the lowermost position of the housing 4 and discharged to the outside from the water discharge hole 9 through the small chamber 10 and the water drain hole 11.
Since the water diffusion portion 12 is formed at the center part of the bottom surface 7 of the recess portion 8, the entering water 17 entering from the water drain hole 11 moves in the circumferential direction along the outer surface of the water diffusion portion 12 as is clear from Figs. 2 to 4 and its momentum is weakened. Since movement of this entering water in the axial direction is small, the entering water does not enter inside from the water discharge holes 9 on the both sides in the axial direction. Reference numerals

1 Rotor
2 Stator
2a Magnet
3 End lid
4 Housing
5 Ring member
6 Rising wall surface
7 Bottom surface
8 Recess portion
9 Water discharge hole

10 Small chamber
11 Water drain hole
12 Water diffusion portion
13 Bearing
14 Output shaft
15 Coil
16 Flange portion
17 Entering water
18 Magnet holder



We Claim:
1. A water drain structure of a fan motor having a cylinder-shaped housing (4) with a
bottom and the opening thereof closed by an end lid (3), in which a rotor (1) and a stator
(2) are accommodated therein; and
a ring member (5) conforming to the outer circumference of the housing (4) and fitted on the outer circumference in the ring state so as to constitute a motor mounting portion and both side of the ring member (5) contact with housing (4) to guard water entering from that, wherein
at a lowermost position of the housing (4) opposite to the ring member (5), a recess portion (8) having a rising wall surface (6) toward the inner surface side and a bottom surface (7) is provided, and a water discharge hole (9) is provided at the root or neighborhood of the rising wall surface (6), wherein
a small chamber (10) is formed between the recess portion (8) and the ring member (5), and a water drain hole (11) is formed at the ring member (5) opposite to the center part of the bottom surface (7); characterized in that
the recess portion (8) is formed in a trapezoidal shape having a height equal to or smaller than the height of the stator (2), and at least one pair of the water discharge holes (9) are provided at the root of the rising wall surface (6) located on both sides of the recess portion (8) in the axial direction of the housing (4).
2. The water drain structure of a fan motor as claimed in claim 1, wherein a water diffusion portion (12) is provided with the arc-state section projecting along the circumferential direction of the housing (4), on the inner surface side at the center part of the bottom surface (7).
3. The water drain structure of a fan motor as claimed in any of claims 1 to 2, wherein
the stator (2) is made of a pair of arc-state magnets (2a), and a lower end edge of the respective magnets (2a) is positioned on the rising wall surface (6) of the recess portion (8).



Documents:

73-del-2007-abstract (04-05-2011).pdf

73-DEL-2007-Abstract-(05-01-2011).pdf

73-del-2007-abstract.pdf

73-del-2007-claims (04-05-2011).pdf

73-DEL-2007-Claims-(05-01-2011).pdf

73-del-2007-claims.pdf

73-DEL-2007-Correspondence Others-(04-05-2011).pdf

73-DEL-2007-Correspondence Others-(04-07-2011).pdf

73-del-2007-correspondence-others (04-05-2011).pdf

73-DEL-2007-Correspondence-Others-(05-01-2011).pdf

73-del-2007-correspondence-others-1.pdf

73-DEL-2007-Correspondence-Others.pdf

73-DEL-2007-Description (Complete)-(04-05-2011).pdf

73-DEL-2007-Description (Complete)-(05-01-2011).pdf

73-del-2007-description (complete).pdf

73-DEL-2007-Drawings-(05-01-2011).pdf

73-del-2007-drawings.pdf

73-DEL-2007-Form-1-(04-05-2011).pdf

73-del-2007-form-1.pdf

73-del-2007-form-18.pdf

73-del-2007-form-2 (04-05-2011).pdf

73-DEL-2007-Form-2-(04-05-2011).pdf

73-del-2007-form-2.pdf

73-DEL-2007-Form-3-(05-01-2011).pdf

73-del-2007-form-3.pdf

73-DEL-2007-Form-5-(04-05-2011).pdf

73-del-2007-form-5.pdf

73-DEL-2007-GPA-(05-01-2011).pdf

73-del-2007-gpa..pdf


Patent Number 248602
Indian Patent Application Number 73/DEL/2007
PG Journal Number 30/2011
Publication Date 29-Jul-2011
Grant Date 27-Jul-2011
Date of Filing 11-Jan-2007
Name of Patentee T. RAD CO., LTD.
Applicant Address 25-3, YOYOGI 3-CHOME, SHIBUYA-KU, TOKYO 151-0053, JAPAN.
Inventors:
# Inventor's Name Inventor's Address
1 KOTA SHIMADA AND SHUICHI MAEZAWA 25-3, YOYOGI 3-CHOME, SHIBUYA-KU, TOKYO 151-0053, JAPAN.
PCT International Classification Number H02K5/10
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 2006-315761 2006-11-22 Japan