CA2375129A1

CA2375129A1 - Heat sink-equipped fan motor and small flat motor

Info

Publication number: CA2375129A1
Application number: CA002375129A
Authority: CA
Inventors: Hisafumi Yasuda
Original assignee: Namiki Precision Jewel Co Ltd
Current assignee: Individual
Priority date: 1999-05-26
Filing date: 2000-05-25
Publication date: 2000-12-07
Also published as: JP2000341902A; CN1354903A; WO2000074213A1

Abstract

A heat sink-equipped fan motor that is small and flat but superior in heat dissipation or air-cooling effect and that is structurally simple as a whole , easily assembled in thin form and inexpensive. A fan motor (M) comprising a rotor (11) and a stator (12) is mounted on substantially the middle of the plate surface of a base plat (10) adapted to be fixed to various devices requiring heat dissipation. A plurality of thin-sheet-like heat dissipating sheets (17) mutually parallelly stacked with a predetermined clearance therebetween and having an opening (17a) formed in the middle of the plate surface for rotatably receiving the fan motor (M) are used to assemble a hea t sink (H) that transfers heat from the base plate (10).

Description

HEAT SINK-EQUIPPED FAN MOTOR AND SMALL FLAT MOTOR
FIELD OF TECHNOLOGY
[0001] This invention deals with a heat sink-equipped fan motor that can be installed on various devices, such as IC's, that require dissipation of heat, and improvement of a small, flat motor that is well-suited to the constitution of that fan motor.
BACKGROUND TECHNOLOGY

[0002] In the past, heat sink-equipped fan motors like that shown in figure 11 have had a base plate 1 that can be fixed to various devices that require dissipation of heat, a fan motor 2 mounted roughly in the center of the base plate 1, multiple heat dissipation blocks 3a, 3b . . . that rise from the inner surface of the base plate 1 directly below the region of rotation of impellers 2a, 2b . . . and lined up like curb stones concentric with the rotating shaft of the fan motor 2. A cover plate 4 is attached to the sides of the base plate 1, with one side left open for the expulsion of air, and the air movement generated by the fan motor 1 forces the cooling of the heat-dissipation blocks 3a, 3b . . .

(0003] Because this heat sink-equipped fan motor has heat-dissipation blocks 3a, 3b . . . located directly below the region of rotation of impellers 2a, 2b . .
., the overall thinness of the motor is limited by the need to maintain space for the rotation of the impellers 2a, 2b . . and by the thickness of the rise of the heat-dissipation blocks 3a, 3b . . . Moreover, because the heat-dissipation blocks 3a, 3b . . . are lined up like curb stones concentric with the rotating shaft of the fan motor 2, the stream of air is obstructed by the heat-dissipation blocks 3a, 3b . . ., and an adequate cooling effect cannot be obtained.

[0004] Regarding that, there have been proposals, in JP H6/141507 and JP

for example, to form the inside of the housing that faces the outer periphery of the impeller as heat-dissipation fins, to make the sides thicker, and to make exhaust grooves with a thickness that corresponds to that of the side walls extend from the rotor circle upstream, so that the air movement generated by the fan motor flows through the grooves and forcibly cools the heat-dissipation fins on the sides.

(0005] In this heat sink-equipped fan motor, because exhaust grooves with a thickness that corresponds to that of the side walls extend from the rotor circle upstream, the heat-dissipation fins that face the outer periphery of the impeller are structurally complex, as well as heavy. Another undesirable feature is the high production cost.

[0006] A known procedure to make this heat sink-equipped fan motor a small, flat motor that is quiet and has a stable rate of revolution is to put helical grooves in opposite directions on the outside of the rotating shaft and the inside of the dynamic pressure sleeve and use a dynamic pressure hydraulic bearing that circulates the oil as the rotor bearing.

[0007] With this dynamic pressure hydraulic bearing, the dynamic pressure sleave is made of brass with good workability, and so the cost of the motor as a whole is increased.

[0008] The purpose of this invention is to provide a heat sink-equipped fan motor which, although small and flat, has a superior heat dissipation and air-cooling effect, and which on the whole has a simple constitution, is easily assembled in a thin package, and is inexpensive.

[0009] A side from this heat sink-equipped fan motor, this invention has the purpose of providing a small, flat motor that can be constituted with an inexpensive dynamic pressure hydraulic bearing that is quiet and has a stable rate of rotation.
SUMMARY OF THE INVENTION

[0010] In the heat sink-equipped fan motor of this invention, there is a base plate to be fixed to various devices that require dissipation of heat, and a fan motor that comprises a rotor and a stator is accommodated, such that the fan motor can rotate, in an opening located over roughly the center of the base plate; the heat sink is assembled to dissipate heat from the base plate by means of multiple thin heat-dissipation fins that are stacked in parallel with a specked gap maintained between them.

[0011] In the heat sink-equipped fan motor of this invention, the heat sink is assembled with a stack of multiple thin heat-dissipation fins with openings to accommodate the fan motor so that it can rotate, the outermost heat-dissipation fin having an opening with a diameter smaller than that of the fan motor.

[0012] In the heat sink-equipped fan motor of this invention, the heat sink is assembled from a stack of multiple thin heat-dissipation fins connected and fixed in place at the corners by a heat-transmitting material that maintains a specified gap between them.

[0013] In the heat sink-equipped fan motor of this invention, there is a base plate formed of aluminum sheet or copper sheet, and the heat sink is assembled of heat-dissipation fins formed of aluminum sheet or copper sheet.

[0014] In the heat sink-equipped fan motor of this invention, there is a fan motor with vertical, L-shaped impellers that are gently arced in the horizontal plane and project outward from the outer periphery of the rotor, with each tip rising inside the opening in the heat-dissipating fins.

[0015] In the heat sink-equipped fan motor of this invention, there is a fan motor with impellers in a flat, branched wing shapes, in multiple, parallel layers at specified intervals along the rotor shaft so that the tips are positioned in the gaps between the base plate and the heat-dissipation fins.

(0016] In the heat sink-equipped fan motor of this invention, the multiple, thin heat-dissipation fins stacked in parallel have circular openings that center on the rotating shaft of the fan motor.

[0017] The small, flat motor of this invention is assembled of a stator with a coil wound on a core, a rotor with a magnet, a bearing that supports a rotor such that it is able to rotate, a bearing housing that supports and fixes in place the stator and that has the rotor bearing penetrating it and fixed within it, and a base plate with the bearing housing fixed to and rising from roughly its center, and the rotor bearing is a dynamic pressure hydraulic bearing that has a dynamic pressure sleeve molded of polymer, with a protruding guard around the periphery, and a stop ring that fits around the outside of the dynamic pressure sleeve to hold down the protruding guard. This dynamic pressure hydraulic bearing is located within the bearing housing that rises roughly from the center of the base plate, and the stop ring that holds down the protruding guard-of the dynamic pressure sleeve is fitted into and fixed to the inside diameter of the bearing housing. The rotor is supported such that it can rotate by the dynamic pressure hydraulic bearing that has a polymer dynamic pressure sleeve.

[0018] In the small, flat motor of this invention, there is a dynamic pressure hydraulic bearing with at least one bore hole in the end of the dynamic pressure sleeve aligned vertically and parallel to the central axis, which is used as an oil reserve, which dynamic pressure hydraulic bearing supports the rotor such that it is able to rotate.

[0019] In the small, flat motor of this invention, there is a dynamic pressure hydraulic bearing with multiple bore holes in the end of the dynamic pressure sleeve spaced at specified intervals and concentric with the central axis, which are used as oil reserves, which dynamic pressure hydraulic bearing supports the rotor such that it is able to rotate.

BRIEF EXPLANATION OF DRAWINGS

[0020] Figure 1 is a sectional side view showing the heat sink-equipped fan motor of this invention.

[0021] Figure 2 is a plane view showing an example of an impeller that can be assembled into that motor.

(0022] Figure 3 is an oblique view of the impeller in figure 2.

[0023] Figure 4 is an oblique view showing the outermost heat-dissipation fin separated from the heat sink-equipped fan motor in figure 1.

[0024] Figure 5 is a plane view showing a different impeller for the heat sink-equipped fan motor of this invention.

[0025] Figure 6 is a sectional side view showing a heat sink-equipped fan motor using the impeller in figure S.

[0026] Figure 7 is a partial sectional side view showing an example of the dynamic pressure fluid bearing used in the small, flat motor of this invention.

[0027] Figure 8 is a plane view showing the dynamic pressure fluid bearing in figure 7.

[0028] Figure 9 is a partial sectional side view showing another example of the dynamic pressure fluid bearing used in the small, flat motor of this invention.

[0029] Figure 10 is a bottom view showing the dynamic pressure fluid bearing in figure 9.

[0030] Figure 11 is an oblique view showing a conventional heat sink-equipped fan motor.
DESCRIPTION OF THE PREFERRED EMBODIMENT

[0031] This explanation is explained below with reference to figures 1 through 10.
Figures 1 through 4 show a heat sink-equipped fan motor in which the fan motor has vertical impellers. Figures 5 and 6 show a heat sink-equipped fan motor in which the fan motor has flat impellers. These heat sink-equipped fan motors have basically the same structural components with the exception of the impellers, and corresponding parts are labelled with the same numbers.

[0032] This heat sink-equipped fan motor is constituted with a small, flat motor. The small, flat motor has a dynamic pressure bearing with the characteristic structure shown in figures 7 through 10. It is appropriate to use as a small, flat drive motor in other applications without the heat sink.

[0033] As a heat sink-equipped fan motor, it can be used on various devices that require dissipation of heat, such as IC's; as shown in figure l, it is constituted on a base plate that is fixed on various devices that require dissipation of heat. This base plate 10 functions as a heat absorbing plate, and can be formed from an aluminum sheet, copper sheet or other material with good thermal conductivity. This base plate 10 is the base for the fan motor, and can be formed in a thickness that will enhance its function of heat absorption.

[0034] The heat sink-equipped fan motor has, roughly at the center of the base plate 10, a motor M that comprises a rotor 11 and a stator 12, and the heat sink H
is located around the periphery of the fan motor M. Within that constitution, the fan motor M
has a bearing housing 13 that rises from and is fixed to roughly the center of the base plate 10, and the rotor 11 is supported, free to tum, by a dynamic pressure hydraulic bearing 14 that is framed by the bearing housing 13. The stator 12 is fixed to and supported by the bearing housing 13.

[0035] The rotor 11 has a ring-shaped magnet 11a; the magnet lla is held by a magnet yoke 11b, and is covered by a circular rotor cap 11c. The rotor 11 has a rotating shaft that is fitted and fixed into the center boss lld of the rotor cap 11c. The rotating shaft penetrates and is supported, free to tum, by the dynamic pressure hydraulic bearing 14, and is thus accommodated by the bearing housing 13 on the base plate 10.

[0036] The stator 12 has a coil 12a wrapped on a core 12b, and the terminals of the coil 12a are connected to motor rotation control elements or other circuit components on a circuit board 12c. This stator 12 is assembled on the bearing housing 13, with the core 12b on which the coil 12a is wrapped fitted and fixed to the top end of the bearing housing 13, and the circuit board 12c fixed in place halfway up the bearing housing 13.

[0037] The fan motor M is constituted with multiple impellers 16a, 16b . . .
around the outer periphery of the rotor cap. These impellers 16a,16b . . . can be, as shown in figures 2 and 3, vertical impellers that are gently arced in the horizontal plane and project outward from the outer periphery of the rotor cap 11c, with each tip rising in an L-shape. The fan motor M rotates in the direction X with the insides of the arcs of the impellers 16a, 16b . . .
facing forward.

[0038] The impellers 16a, 16b . . ., including the central ring 16c, are die-cast as a whole of aluminum or another material with excellent heat-dissipation characteristics.

Further, the impellers 16a, 16b . . . are formed separately from the rotor cap 11c, and are fitted and fixed to the outer periphery of the rotor cap 11c by means of the central ring 16c.

[0039] The heat sink H is arranged around the outer edge of the fan motor M, maintaining a space in the center that accommodates, so that it is free to turn, the fan motor M including the roughly L-shaped impellers 16a,16b . . . As shown in figure 4, this heat sink H is constituted of multiple heat-dissipation fins 17 . . . having at their center an opening 17a that accommodates the fan motor M and allows it to rotate. These heat-dissipation fins 17 . . .
are thin sheets cut in rectangular shape from a material with good thermal conductivity such as aluminum sheet or copper sheet; the heat sink H is assembled by stacking multiple fins in parallel, maintaining a specified gap between them.

[0040] The heat-dissipation fins . . . are assembled using spacers 17b and rivets 17c made of aluminum or another material with good thermal conductivity; the spacers 17b are sandwiched between the base plate 10 and the corners of the individual heat-dissipation fins 17 . . . to maintain the specified gaps between them, and the rivets 17c penetrates the fins and the spacers 17b so that the base plate 10 and the heat-dissipation fins 17 . .
. are connected and fixed, and so that heat can be conducted away from the base plate 10.

[0041] In the heat sink-equipped fan motor constituted in this manner, because the heat sink H is assembled around the fan motor M, maintaining at its center a space that accommodates the fan motor M so it is free to rotate, it can be made with a flat thickness of the base plate 10 plus the height of the fan motor M.

[0042] The heat sink H is constituted by stacking in parallel multiple thin heat-dissipation fins 17 . . . formed by cutting rectangular shapes from aluminum sheet or copper sheet with good thermal conductivity, with central openings 17a that accommodate the fan motor M so that it is able to rotate, and so it is structurally simple and easy to assemble.

[0043] The spacers 17b are sandwiched between the base plate 10 and the comers of the individual heat-dissipation fins 17 . . . to maintain the specified gap between them, and the rivets 17c penetrate the individual fins and the spacers 17b and connect and fix the heat dissipation fins 17 . . . to the base plate 10 so that heat can be conducted quickly away from the base plate 10.

[0044] Moreover, because the thin heat-dissipation fins 17 . . . are assembled by stacking them in parallel, it is possible to ensure a large heat-dissipation area for the heat-dissipation fins 17 . . . And because the air movement generated by the impellers 16a, 16b . . . of the fan motor M is used to dissipate heat from each of the heat-dissipation fins 17 . . ., the heat that is conducted to the heat-dissipation fins 17 . . .
from the base plate 10 can be dissipated efficiently.

[0045] In addition to that, the impellers 16a, 16b . . . of the fan motor M
are mounted vertically with the tips rising to form a rough L-shape, and so they can generate a great volume of air movement and thus cool the heat-dissipation fins 17 . . .
efficiently.

[0046] The heat sink H can be assembled by stacking multiple heat dissipation fins 17 . . ., each having an opening 17a that accommodates the fan motor M so that it is free to rotate, as stated above, and also a final heat-dissipation fin 18 that has an opening 18a with a diameter smaller than the diameter of the rotor cap 11a. By this means, there is an aperture for the intake of air into the openings 17a of the heat-dissipation fins 17 .
. ., and the air moved by the fan motor M is prevented from escaping, so that the heat-dissipation fins 17 . . .
can function efficiently and heat can be dissipated efficiently by the heat-dissipation fins 17 . . .,18.

[0047] In place of the vertical impellers 16a, 16b . . . described above, it is possible for the fan motor M to be constituted with multiple branched, wing-shaped impellers 160 . . .
as shown in figure 5. These impellers 160 . . . are based on a central ring 161, with multiple wings 160a through 160d that are connected to the ring 161 by adjacent main stems 162, and branches 163, 164 that extend from the main stems 162 and are roughly perpendicular to them, all punched as a unit from flat stock.

[0048] As shown in figure 6, the central rings 161 of multiple impellers 160 are fixed sandwiched between spacer rings 165a through 165d, and spacer rings 165a through 165d are fitted over the outer periphery of the rotor cap 11c and fixed in place so that they extend radially from the rotor 11, and are parallel, separated by a specified gap.
Further, the tips of the wings 160a through 160d of each impeller 160 . . . are located in the spaces between the base plate 10 and the heat-dissipation fins 15 . . . ,18, and so are able to rotate.

[0049] The impellers 160 . . . are formed simply by punching from thin sheets, and are able to ensure an adequate volume of air movement generated by the multi-branched shape. Particularly because the tips of the wings 160a through 160d of each impeller 160 . . .
are located in the spaces between the base plate 10 and the heat-dissipation fins 15 . . . , 18, the air movement generated by the tips located in the spaces between the base plate 10 and the heat-dissipation fins 15 . . . , 18 can function efficiently the base plate 10 and the heat-dissipation fins 15 . . . , 18. Now, the mufti-branched shape is not limited to the shape shown in the figure; it is possible to change the design of the mufti-branched shape as appropriate.

[0050] In each of the multiple heat-dissipation fins 17 of the heat sink H
there is a circular opening 17a centered on the rotating shaft of the fan motor, and because there is no edge portion to obstruct the air movement generated by the fan motor, the noise created by the edge cutting the air is prevented, resulting in a low-noise fan motor.

[0051] The fan motor M is best constituted so that the rotor 11 is supported, such that it is able to rotate, by the dynamic pressure hydraulic bearing 14 mounted within the bearing housing 13, as shown in figure 7. By supporting the rotating shaft 15 so that the oil flow is circulated by having helical grooves 141a,141b in the dynamic pressure hydraulic bearing 14 to provide up and down motion between the outside of the rotating shaft 15 and the inside of the inside of the dynamic pressure sleeve 140, it is possible to constitute a small, flat motor with low noise and a stable rate of rotation.

[0052] The dynamic pressure hydraulic bearing 14 has a molded polymer hydraulic pressure sleeve 140 with a protruding guard 142 around the outside, and a stop ring 143 that is fitted around the outside of the dynamic pressure sleeve 140 and that holds down the protruding guard 142. The dynamic pressure sleeve 140 is located within the bearing housing 13 that rises from roughly the center of the base plate 10, and the stop ring 143 that holds down the protruding guard 142 of the dynamic pressure sleeve 140 is fitted and fixed to the inside circumference of the bearing housing 13.

[0053] The dynamic pressure hydraulic bearing 14 can be constituted inexpensively using the polymer dynamic pressure sleeve 140. And because the protruding guard 142 of the dynamic pressure sleeve 140 is held down by the stop ring 143 that is fitted and fixed to the inside circumference of the bearing housing 13, no pressure is applied in the direction of the circumference of the dynamic pressure sleeve 140 by the insertion and fixing of the dynamic pressure sleeve 140 inside the bearing house 13, and no impact on the degree of precision of the inner circumference of the bearing. And so a drive motor with low noise and a stable rate of rotation can be constituted using a polymer dynamic pressure sleeve 140.

[0054] In the dynamic pressure hydraulic bearing 14, when there are rounded slide ribs 144a through 144d established vertically at specified intervals around the outer edge of the protruding guard 142, as shown in figure 8, the dynamic pressure sleeve 140 can easily be inserted and fixed inside the bearing housing 13. And by establishing grooves 145a, 145b in the top surface of the protruding stop ring 142, it is possible to insert the stop ring 143 into the bearing housing 13 and fix it firmly, unable to rotate, by meshing the grooves 145a, 145b with projections (not illustrated) on the stop ring 143.

[0055] Making use of this dynamic pressure hydraulic bearing 14, the magnetic action of the coil 12a of the stator 12 and the magnet lla of the rotor 11 will pull the rotor as a whole in the direction of mounting in the stator 12, and the dynamic pressure hydraulic bearing 14 will support the rotor 11 so that it is able to rotate stably. In addition, it can be assembled with a thruster 19 that faces the end of the rotating shaft 15 of the rotor 15, as shown in figures 1 and 5, so that the rotor 11 can rotate smoothly.

[0056] In the dynamic pressure bearing 14, there can be at least one bore hole 146 in the end of the dynamic pressure sleeve, aligned vertically and parallel to the central axis, which is used as an oil reserve, as shown in figure 9. If there is an oil reserve in the form of this bore hole 146, it is possible to prevent the loss of oil through deterioration during continued use that accompanies the bearing heat produced when operating at about 8090, and the life of the bearing can be extended.

[0057] This bore hole used as an oil reserve can take the form, as shown in figure 10, of multiple holes 146 through 146g, spaced at specified intervals in a concentric ring on the end of the dynamic pressure sleeve 140, and can effectively prevent the loss of oil through deterioration during continued use that accompanies the production of heat. By establishing grooves 147a,147b that connect either one bore hole 146 or opposing bore holes 146,146d to the edge, it is possible to have a thruster 19 that faces the shaft end of the rotating shaft 15 of the rotor 11, and enable it to rotate smoothly INDUSTRIAL UTILITY

[0058] As stated above, in the heat sink-equipped fan motor of this invention, by having a fan motor that is accommodated, such that the fan motor can rotate, in an opening in roughly the center of the fins of the heat sink that is assembled to dissipate heat from the base plate by means of multiple thin heat-dissipation fins that are stacked in parallel with a specified gap maintained between them, it is possible to have a thin, flat, shape with a simple and easily assembled structure that is no thicker than the combined thickness of the base plate and the fan motor, it is possible to assure a large heat-dissipation area for each of the heat-dissipation fins that are stacked in parallel, and it is possible to dissipate efficiently the heat conducted to the heat-dissipation fins from the base plate by the action of the air movement generated by the fan motor on each of the thin heat-dissipation fins.

[0059] In the heat sink-equipped fan motor of this invention, the heat sink is assembled with a stack of multiple thin heat-dissipation fins with openings to accommodate the fan motor so that it can rotate, the outermost heat-dissipation fin having an opening with a diameter smaller than that of the fan motor, and so there is an aperture for the intake of air into the openings of the heat-dissipation fins, and the air moved by the fan motor is prevented from escaping, so that the air pressure can work efficiently on the heat-dissipation fins.

[0060] In the heat sink-equipped fan motor of this invention, the heat sink is assembled from a stack of multiple thin heat-dissipation fins connected and fixed in place at the corners by a heat-transmitting material that maintains a specified gap between them, and so the heat sink can be assembled such that it can conduct heat from the base plate quickly.

[0061] In the heat sink-equipped fan motor of this invention, there is a base plate formed of aluminum sheet or copper sheet, and the heat sink is assembled of heat-dissipation fins formed of aluminum sheet or copper sheet, and so the heat sink is able to conduct heat from the base plate quickly.

[0062] In the heat sink-equipped fan motor of this invention, there is a fan motor with vertical, L-shaped impellers that are gently arced in the horizontal plane and project outward from the outer periphery of the rotor, with each tip rising inside the opening in the heat-dissipating fins, and so the air movement generated by the impeller tips is able to work efficiently on the base plate and heat-dissipation fins.

[0063] In the heat sink-equipped fan motor of this invention, there is a fan motor with impellers in flat, branched wing shapes, in multiple, parallel layers at specified intervals along the rotor shaft so that the tips are positioned in the gaps between the base plate and the heat-dissipation fins, and so the air movement generated by the tips of the impellers can function efficiently on the base plate and the heat-dissipation fins.

[0064] In the heat sink-equipped fan motor of this invention, the multiple heat-dissipation fins 17 of the heat sink H have circular openings 17a that center on the rotating shaft of the fan motor and there is no edge to interrupt the air movement generated by the fan motor, so that it is possible to constitute a low-noise fan motor that does not produce a sound by cutting the air.

[0065] In the small, flat motor of this invention, the rotor bearing is a dynamic pressure hydraulic bearing that has a dynamic pressure sleeve molded of polymer, with a protruding guard around the periphery, and a stop ring that fits around the outside of the dynamic pressure sleeve to hold down the protruding guard. This dynamic pressure hydraulic bearing is located within the bearing housing that rises roughly from the center of the base plate, and the stop ring that holds down the protruding guard of the dynamic pressure sleeve is fitted into and fixed to the inside diameter of the bearing housing.
Therefore, it can be constituted inexpensively with a polymer dynamic pressure sleeve, and no pressure is applied to the circumference of the dynamic pressure sleeve, so that it is possible to constitute a drive motor with stable precision of the inner circumference of the bearing, even though it uses a polymer dynamic pressure sleeve.

[0066] In the small, flat motor of this invention, there is a dynamic pressure hydraulic bearing with at least one bore hole in the end of the dynamic pressure sleeve aligned vertically and parallel to the central axis, which is used as an oil reserve, which dynamic pressure hydraulic bearing supports the rotor such that it is able to rotate, and so it is possible to effectively prevent the loss of oil through deterioration during continued use that accompanies the production of heat, and thus extend the life of the bearing.

[0067] In the small, flat motor of this invention, there is a dynamic pressure hydraulic bearing with multiple bore holes in the end of the dynamic pressure sleeve spaced at specified intervals and concentric with the central axis, which are used as oil reserves, which dynamic pressure hydraulic bearing supports the rotor such that it is able to rotate, and so it is possible to effectively prevent the loss of oil through deterioration during continued use that accompanies the production of heat, and thus extend the life of the bearing.

[0068] The terms and expressions used above in the description of this invention are used solely for the purpose of explanation, and do not limit the substance of the invention in any way. In the event that limiting terms or expressions have been used, there is no intention thereby to exclude configurations or parts equivalent to this invention as described above. It is clear, therefore, that it is possible to make various changes that are within the realm of this invention for which rights have been claimed.

Claims

CLAIMS:

1. In the heat sink-equipped fan motor having a base plate to be fixed to various devices that require dissipation of heat, and a fan motor that comprises a rotor and a stator that is located over roughly the center of the base plate, with the heat sink around the outside of the fan motor;
in which the fan motor is accommodated, such that it can rotate, in an opening at the center of the base plate, the heat sink being assembled to dissipate heat from the base plate by means of multiple thin heat-dissipation fins that are stacked in parallel with a specified gap maintained between them.

2. A heat sink-equipped fan motor as described in claim 1 above, in which the heat sink is assembled with a stack of multiple thin heat-dissipation fins with openings to accommodate the fan motor so that it can rotate, the outermost heat-dissipation fin having an opening with a diameter smaller than that of the fan motor.

3. A heat sink-equipped fan motor as described in claim 1 or 2 above, in which the heat sink is assembled from a stack of multiple thin heat-dissipation fins connected and fixed in place at the corners by a heat-transmitting material that maintains a specified gap between them.

4. A heat sink-equipped fan motor as described in any of claims 1 through 3 above, in which there is a base plate formed of aluminum sheet or copper sheet, and the heat sink is assembled of heat-dissipation fins formed of aluminum sheet or copper sheet.

5. A heat sink-equipped fan motor as described in any of claims 1 through 4 above, in which there is a fan motor with vertical, L-shaped impellers that are gently arced in the horizontal plane and project outward from the outer periphery of the rotor, with each tip rising inside the opening in the heat-dissipating fins.

6. A heat sink-equipped fan motor as described in any of claims 1 through 4 above, in which there is a fan motor with impellers in a flat, branched wing shapes, in multiple, parallel layers at specified intervals along the rotor shaft so that the tips are positioned in the gaps between the base plate and the heat-dissipation fins.

7. A heat sink-equipped fan motor as described in any of claims 1 through 6 above, in which the multiple, thin heat-dissipation fins stacked in parallel have circular openings that center on the rotating shaft of the fan motor.

8. A small, flat motor assembled of a stator with a coil wound on a core, a rotor with a magnet, a bearing that supports a rotor such that it is able to rotate, a bearing housing that supports and fixes in place the stator and that has the rotor bearing penetrating it and fixed within it, and a base plate with the bearing housing fixed to and rising from roughly its center;
in which the rotor bearing is a dynamic pressure hydraulic bearing that has a dynamic pressure sleeve molded of polymer, with a protruding guard around the periphery, and a stop ring that fits around the outside of the dynamic pressure sleeve to hold down the protruding guard, the dynamic pressure hydraulic bearing being located within the bearing housing that rises roughly from the center of the base plate, and the stop ring that holds down the protruding guard of the dynamic pressure sleeve is fitted into and fixed to the inside diameter of the bearing housing, with the rotor supported such that it can rotate by the dynamic pressure hydraulic bearing that has a polymer dynamic pressure sleeve.

9. A small, flat motor as described in claim 8 above, in which there is a dynamic pressure hydraulic bearing with at least one bore hole in the end of the dynamic pressure sleeve aligned vertically and parallel to the central axis, which is used as an oil reserve, which dynamic pressure hydraulic bearing supports the rotor such that it is able to rotate.

10. A small, flat motor as described in claim 8 above, in which there is a dynamic pressure hydraulic bearing with multiple bore holes in the end of the dynamic pressure sleeve spaced at specified intervals and concentric with the central axis, which are used as oil reserves, which dynamic pressure hydraulic bearing supports the rotor such that it is able to rotate.