JP5540547B2 - Inner rotor type brushless motor and cooling fan - Google Patents

Description

  The present invention particularly relates to a battery cooling fan drive motor that cools a battery mounted on a vehicle such as a hybrid vehicle, and more particularly to a structure that is improved in durability against vibration and impact, and is reduced in weight and thickness. Is.

  2. Description of the Related Art In recent years, a hybrid vehicle that has begun to spread rapidly and an electric vehicle that will attract attention in the future are equipped with a motor as a power source and a rechargeable battery that supplies electric energy to the motor. This battery is configured by further connecting a plurality of battery modules in which a plurality of battery cells are connected in series. Furthermore, electric and electronic parts such as a relay for opening and closing the connection between the battery and the motor drive circuit of the automobile are incorporated to constitute a battery pack.

  In general, the temperature of a battery rises due to heat generation during charging / discharging and is likely to be overcharged, and the deterioration is accelerated under a high temperature environment. In addition, the temperature rise of the battery in the vicinity of the heat generating electrical / electronic components is increased.

  As a countermeasure, the battery pack incorporates a cooling fan for the battery and a cooling fan for electric and electronic parts to suppress the temperature rise of the battery.

  In addition, battery packs are placed under the rear seats of hybrid vehicles, behind the trunk room, or under the car body, so they are required to be thinner and smaller. However, depending on the location of the battery pack, the fan motor is waterproof. When the waterproof measure is installed as a countermeasure, there is a problem that the fan motor is thick and large contrary to the requirement.

  In order to meet this demand, a technique for reducing the size of a battery pack by efficiently laying out a cooling fan for electric / electronic parts and a cooling fan for a battery in a limited space has been proposed. (For example, refer to Patent Document 1).

  However, although the conventional configuration disclosed in Patent Document 1 has been reduced in size, the problem of reduction in thickness has not been solved.

  In order to reduce the thickness of the battery pack, it is required to reduce the thickness of the cooling fan. A centrifugal fan has been proposed in which the electronic components of a control circuit that controls the rotation of the cooling fan are arranged on the radially outer side of the peripheral wall of the fan casing, thereby reducing the axial dimension and reducing the thickness. (For example, refer to Patent Document 2).

FIG. 4 shows the structure of the cooling fan described in Patent Document 2. In FIG. 4, a centrifugal fan 3001 includes an impeller 3003 having a plurality of blades around a central axis 3002, a motor 3004 that rotationally drives the impeller 3003, a control circuit unit 3005 that controls the rotation of the motor 3004, an impeller 3003, A casing 3006 for housing the motor 3004 and the control circuit unit 3005 is provided. The electronic component 3007 constituting the control circuit unit 3005 is an electron formed between a virtual extension surface S obtained by extending the opening end surface of the exhaust port of the casing 3006 in a direction perpendicular to the central axis 3002 and the peripheral wall 3008 of the casing 3006. Arranged in the component arrangement unit 3009. In the centrifugal fan 3001, the electronic component 3007 is disposed on the outer side in the radial direction of the air flow path 3010. Therefore, the axial dimension of the centrifugal fan 3001 can be suppressed, and a reduction in thickness can be realized.

JP 2006-24510 A JP 2008-215330 A

  Since motors mounted on automobiles are required to have durability against vibration and impact, it is necessary to reduce the weight of the rotor and increase the rigidity to improve durability against vibration and impact.

  However, in the conventional configuration disclosed in Patent Document 2, the thickness is reduced, but the problem of improving durability against vibration and impact is not solved. In particular, in the conventional configuration shown in Patent Document 2, the cooling fan driving motor to which the fan (impeller) 3003 is attached has the fan 3003 and the rotor 3011 fixed to one side of the central shaft 3002, so that vibration / impact Therefore, a large bending moment is likely to be generated in the shaft fixing portion of the rotor 3011. Due to this moment, the rotor 3011 may be deformed to generate vibration and noise during the rotation of the motor, or the bearing life may be significantly reduced due to shaft rotation.

  The present invention solves such problems, and an object of the present invention is to provide a motor that is thin and has improved durability against vibration and impact.

In order to solve the above-described problems, the present invention includes a cup-shaped rotor yoke and a lid, and inserts and fixes the lid on the opening side of the rotor yoke, and shafts in the centers of the rotor yoke and the lid, respectively. A rotor having a magnet fixed to the outer periphery of a rotor yoke assembly formed by fixing, a stator made of an iron core disposed opposite to the magnet and wound, and two supporting the rotor shaft A bearing, a cup-shaped frame that inserts the stator and holds one of the bearings on the top surface, and a bearing holding portion that is attached to cover the opening side of the frame and holds the other of the bearings in the center are formed. And at least one of the end surface portion opposite to the opening side of the rotor yoke or the lid body, and the inner side in the axial direction of the rotor yoke. The projecting portion is provided toward, housing at least a portion of said other bearing radially inwardly of the projecting portion, the outer peripheral portion of the lid is in contact with also the outer peripheral portion to the inner diameter portion of the rotor yoke in a circular shape A circular fixing hole for fixing the shaft at the center is provided in the lid body so that the center of the fixing hole coincides, and the lid body abuts at the end portion on the opening side of the rotor yoke and is fitted to the rotor yoke. It is set as the structure which carries out.

  ADVANTAGE OF THE INVENTION According to this invention, the durability improvement with respect to the vibration and the impact of the motor for fan drive for battery cooling which cools the battery mounted in vehicles, such as a hybrid vehicle, weight reduction and thickness reduction can be achieved.

According to the first to third aspects of the present invention, since the shaft is fixed in a state where the lid is inserted and fixed to the opening of the cup-shaped rotor yoke, the rigidity of the rotor yoke assembly is improved, and the vibration / impact is prevented. High durability can be achieved. In addition, because it is supported by two bearings located outside both ends of the rotor in the axial direction, the bending moment of the shaft due to vibration / impact and the run-out moment due to unbalance of the rotor are greatly reduced, and the vibration / impact of the motor It has the effect that the durability with respect to can be improved. Further, since at least a part of one of the bearings that supports the shaft of the rotor is accommodated radially inside the projecting portion formed toward the inner side in the axial direction of the rotor yoke, an increase in the axial height dimension of the motor is suppressed. Can do. In addition, it is possible to realize an excellent motor with outstanding characteristics such as a hollow rotor structure and high responsiveness due to a small moment of inertia, and high durability against vibration and impact because the rotor is light and rigid. it can.

  In addition to the effects of the inventions described in claims 1 to 3, the invention described in claim 4 is arranged on the load side of the shaft by a configuration in which the overhanging portion is formed on the side opposite to the load side of the shaft. Since the outer diameter of the bearing is not restricted by the inner diameter of the overhang, it can be set large, and when using a sintered oil-impregnated shaft, it is long enough to ensure a sufficient amount of lubricating oil. It has the effect that lifetime can be achieved. Further, since the bearing can be arranged at a position close to the operating point of the load on the shaft, the load applied to the bearing can be reduced.

  According to the fifth aspect of the present invention, a part of the lid is formed to have a larger diameter than the cup-shaped rotor yoke, and a magnet is brought into contact with the larger-diameter portion of the lid than the cup-shaped rotor yoke to form a rotor yoke assembly. In addition to the feature that the durability against the vibration / impact of the motor can be improved and the responsiveness is high, the magnet is brought into contact with the rotor yoke by bringing the magnet into contact with a larger diameter portion than the cup-shaped rotor yoke of the lid. Positioning when fixing the magnet can be easily performed, and by providing a space for accommodating the protruding adhesive used to fix the magnet, it is possible to simplify the assembly by eliminating the trouble of wiping off the protruding adhesive. .

  The invention according to claim 6 uses the motor having the structure according to claims 1 to 5 for driving a battery cooling fan that cools a battery mounted on a vehicle such as a hybrid vehicle. It has the effect that durability against vibration and impact can be improved, and the weight and thickness can be reduced.

1 is a sectional structural view showing a motor according to a first embodiment of the present invention. Sectional structure figure which shows the motor by Embodiment 2 of this invention. Sectional structure figure which shows the motor by Embodiment 3 of this invention. Cross-sectional structure diagram of a cooling fan driven by a conventional motor

  The best mode for carrying out the present invention will be described below with reference to the drawings.

(Embodiment 1)
FIG. 1 is a sectional structural view of a motor according to Embodiment 1 of the present invention.

  In FIG. 1, a stator constituted by an iron core 1210 provided with a winding 1220 is fixed to an inner peripheral surface of a frame 1410 formed in a cup shape. Then, facing the inner peripheral side of the stator, a rotor yoke 1121 formed in a cup shape, a lid body 1120 fixed to the opening side of the rotor yoke 1121, and the rotor yoke 1121 and the center of the lid body 1120 are fixed through. A rotor yoke assembly 1125 formed by the shaft 1110 is disposed.

  An inner diameter enlarged portion 1123 in which the inner diameter of the opening is enlarged is formed on the opening side of the rotor yoke 1121, and the outer diameter of the lid 1120 is set to a size that fits the inner diameter of the inner diameter enlarged portion 1123. In addition, a protruding portion 1122 is formed on the lid 1120 toward the inner side in the axial direction of the rotor yoke 1121.

  Then, a cylindrical magnet 1130 is fixed to the outer peripheral surface of the rotor yoke assembly 1125 to constitute the rotor 1100.

A printed circuit board 1521 is attached to the end surface of the opening of the frame 1410. A circuit board for driving the motor, a Hall element for detecting the magnetic pole position of the magnet 1130, and the like are mounted on the printed board 1521. A wiring pattern in which these component leads and the terminal of the stator winding 1220 are connected. Is formed. A bracket 1420 is attached to the opening side of the frame 1410 so as to enclose the printed board 1521 and cover the opening of the frame 1410. A cylindrical bearing holding portion 1510 is formed at the center of the bracket 1420 so as to protrude toward the frame 1410 side. A bearing 1301 is fixed to the center of the top surface of the frame 1410, and a bearing 1302 is press-fitted and fixed to the inner wall of the bearing holding portion 1510 of the bracket 1420. An end cap 1430 is inserted and fixed in the base side opening of the bearing holding portion 1510 at the center of the bracket 1420. The end of the shaft 1110 on the non - output side is spherically processed and is supported in the thrust direction by an end cap 1430 via a thrust plate 1304. The rotor 1100 is rotatably supported by the two bearings 1301 and 1302 and the thrust plate 1304.

  Here, the outer diameter D62 of the bearing holding portion 1510 of the bracket 1420 is set to be smaller than the inner diameter D61 of the protruding portion 1122 of the lid 1120, and is fixed to the bearing holding portion 1510 on the radially inner side of the protruding portion 1122. The bearing 1302 is accommodated at least partially.

  With this configuration, the rotor 1100 is fixed to and integrated with the shaft 1110 at both ends of the rotor 1100 in the axial direction, so that rigidity can be increased. And since the rotor yoke assembly 1125 is integrated, there is no fixed part that may move even when a vibration or impact is applied in the thrust direction, thus realizing a brushless motor with high durability against vibration and impact. Has the effect of being able to.

  In addition, it is possible to realize an excellent motor having distinctive features such as a hollow rotor structure and high responsiveness due to a small moment of inertia, and high durability against vibration and impact because the rotor is light and highly rigid. .

  Since the rotor 1100 is supported by the bearings 1301 and 1302 outside both ends in the axial direction, the shaft turning moment due to unbalance or vibration / impact of the rotor 1100 is greatly reduced.

  Furthermore, since at least a part of the axial height dimension of the bearing 1302 fixed to the bracket 1420 side can be accommodated in the hollow portion inside the axial direction of the rotor yoke 1121, an increase in the axial height dimension of the motor is suppressed. Can do.

  As described above, durability against vibration and impact can be improved, and the weight and thickness can be reduced.

  In the present embodiment, a protruding portion 1124 for fixing (press-fitting) the shaft 1110 to the center of the end surface portion opposite to the opening of the rotor yoke 1121 is formed inward in the axial direction. Yes. On the other hand, the protruding portion is not formed on the lid 1120. After the rotor yoke 1121 and the lid body 1120 are engaged and integrated by the inner diameter enlarged portion 1123, the shaft 1110 passes through the protruding portion 1124 of the rotor yoke 1121 and the center of the lid body 1120 and is fixed by press fitting or the like.

According to such a configuration, the lid body 1120 can process the coaxiality of the outer periphery with respect to the shaft 1110 fixing portion (hole) with high accuracy, so that the swing of the rotor yoke 1121 in which the protruding portion 1124 is formed has no protruding portion. The effect | action and effect that it can correct and correct easily according to the body 1120 can be show | played.

  Furthermore, in the present embodiment, the overhanging portion 1122 is formed on the opposite side (the bracket 1420 side) to the load side (the frame 1410 side) of the shaft 1110, so that the bearing 1301 disposed on the load side of the shaft 1110. Since the outer diameter is not restricted by the inner diameter dimension D61 of the overhanging portion 1122, it can be set larger. As a result, when a sintered oil-impregnated shaft is used as the bearing 1301, it is possible to ensure a sufficient oil retention amount of the lubricating oil, thereby achieving an effect of extending the life. In addition, since the bearing 1301 can be arranged at a position close to the load acting point of the shaft 1110, the load applied to the bearing 1301 can be reduced.

(Embodiment 2)
FIG. 2 is a sectional structural view of a motor according to Embodiment 2 of the present invention.

  In FIG. 2, parts having the same functions as those in FIG.

  In FIG. 2, the configuration of the rotor yoke assembly 1125 is different from that shown in FIG. 1, and a lid 1120 is arranged on the upper side in the axial direction and a rotor yoke 1121 is arranged on the lower side. An overhang 1122 is formed on the end surface of the rotor yoke 1121 opposite to the opening side rather than the lid 1120 toward the inner side in the axial direction of the rotor yoke 1121. Other configurations are the same.

  Even in such a configuration, the same operations and effects as those of the first embodiment can be achieved.

  In the present embodiment, the protruding portion 1124 is formed in the center of the protruding portion 1122 of the rotor yoke 1121 so as to face inward in the axial direction, and the protruding portion is not formed in the lid body 1120. Even if the protruding portion 1124 is formed inward in the axial direction and the protruding portion 1122 of the rotor yoke 1121 is not formed with the protruding portion, the same operation and effect can be obtained.

(Embodiment 3)
FIG. 3 is a sectional structural view of a motor according to Embodiment 3 of the present invention.

  In FIG. 3, parts having the same functions as those in FIG. 1 are denoted by the same reference numerals as those in FIG.

  3, the configuration of the rotor yoke assembly 1125 is the same as that of FIG. 2, and a lid 1120 is disposed on the upper side in the axial direction, and a rotor yoke 1121 is disposed on the lower side. An overhanging portion 1122 is formed on both the lid 1120 and the end surface portion of the rotor yoke 1121 opposite to the opening portion side toward the inner side in the axial direction. A waterproof bearing 1303 is fixed to the top surface of the frame 1410, and a part of the waterproof bearing 1303 is accommodated in the protruding portion of the lid 1120. The wiring of the printed circuit board 1521 is led out from the bracket 1420 by a lead wire 1522 through a waterproof grommet 1523, and forms a sealed structure to constitute a waterproof motor. Further, the outer diameter of the lid 1120 is formed larger than that of the cup-shaped rotor yoke 1121, and the rotor yoke assembly 1125 is formed by bringing the magnet 1130 into contact with the large diameter portion, and the opening of the rotor yoke 1121 is formed. Is formed with a space 1126 for accommodating the protruding adhesive. Other configurations are the same as those in FIG.

Even in such a configuration, it is possible to achieve the same operations and effects as in the first embodiment, although the waterproof motor is normally thick and large.

  Further, the magnet 1130 is brought into contact with a larger diameter portion than the cup-shaped rotor yoke 1121 of the lid 1120 so that positioning when the magnet 1130 is fixed to the rotor yoke 1121 can be easily performed, and an adhesive used when fixing the magnet 1130 is used. By providing the space 1126 that accommodates the protrusion of the agent, an effect that the assembly can be simplified can be obtained.

  In the present embodiment, the protruding portion 1124 is formed in the center of the protruding portion 1122 of the rotor yoke 1121 so as to face inward in the axial direction, and the protruding portion is not formed on the lid body 1120. Even if the protruding portion 1124 is formed in the center of the portion 1122 so as to face inward in the axial direction and the protruding portion 1122 of the rotor yoke 1121 is not formed with the protruding portion, the same operation and effect can be obtained.

  In the above description, the rotor yoke or the lid has been described as an example having a shape having a protruding portion for fixing the shaft. However, when a component such as a boss for fixing the rotor yoke and the shaft is separately provided. The same can be applied to.

The brushless motor according to the present invention can be improved in durability against vibration and impact, and can be reduced in weight and thickness. Therefore, the brushless motor as a battery cooling fan driving motor that cools a battery mounted on a vehicle such as a hybrid vehicle. Useful.
(Other example 1)
The brushless motor according to the present invention is thin and has a small moment of inertia of the rotor and good responsiveness. Therefore, a motor for driving a mechanism of office equipment such as a printer or a copy machine where starting characteristics are important, various valves and oil of an automobile It is also useful as a motor for driving a pump, various manipulators, and a motor for driving a joint of a small robot.

DESCRIPTION OF SYMBOLS 1100, 3011 Rotor 1110 Shaft 1120 Cover body 1121 Rotor yoke 1122 Overhang | projection part 1123 Inner diameter enlarged part 1124 Protrusion part for shaft fixation 1125 Rotor yoke assembly 1126 Space which accommodates the protrusion of an adhesive 1130 Magnet 1210 Iron core 1220 Winding 1301, 1302 3012, 3013 Bearing 1303 Waterproof bearing 1304 Thrust plate 1410 Frame 1420 Bracket 1430 End cap 1510 Bearing holding part 1521 Printed circuit board 1522 Lead wire 1523 Waterproof grommet 3001 Centrifugal fan 3002 Central shaft 3003 Impeller 3004 Motor 3005 Control circuit part 3006 Casing part 3006 Peripheral wall 3009 Electronic component placement part 3010 Empty Passage S imaginary extension plane D61 lid overhang inside diameter D62 bearing holding portion outer diameter

Claims (6)

An outer periphery of a rotor yoke assembly comprising a cup-shaped rotor yoke and a lid, wherein the lid is inserted and fixed to the opening side of the rotor yoke, and a shaft is fixed to the center of each of the rotor yoke and the lid. A rotor having a magnet fixed thereto, a stator made of an iron core disposed opposite to the magnet and provided with windings, two bearings for supporting the shaft of the rotor, and the stator inserted into the top surface A cup-shaped frame that holds one of the bearings, and a bracket that is attached to cover the opening side of the frame and that has a bearing holding part that holds the other of the bearings in the center. A projecting portion is provided on at least one of the end surface portion opposite to the opening side or the lid body toward the inner side in the axial direction of the rotor yoke. A circle for accommodating at least a part of the bearing radially inward of the shim, the outer periphery of the lid having a circular shape, contacting the inner diameter of the rotor yoke, and fixing the shaft to the center of the outer periphery An inner rotor type brushless motor configured such that a fixing hole having a shape is provided in the lid body so that the center of the fixing hole coincides, and the lid body abuts at an opening side end portion of the rotor yoke and is fitted to the rotor yoke. Said projecting portion is formed on the lid, an inner rotor brushless motor according to claim 1, a collision-out out portion for securing said shaft only in the rotor yoke disposed in the axial direction inside the rotor yoke. Said projecting portion is formed in the rotor yoke, an inner rotor type brushless motor according to claim 1, a collision-out out portion for securing said shaft only in the rotor yoke disposed in the axial direction inside the rotor yoke. The inner rotor type brushless motor according to any one of claims 1 to 3, wherein the projecting portion is formed on a side opposite to a load side of the shaft. The outer periphery of the lid is formed in a flange shape with a larger diameter than the cup-shaped rotor yoke, and the end of the magnet (magnet end) is formed on the larger diameter than the cup-shaped rotor yoke of the lid. The rotor yoke assembly is formed so that a space is formed in the cup-shaped mouth side end portion of the rotor yoke by making the cup-shaped mouth side end portion of the rotor yoke shorter than the magnet end portion. Rotor type brushless motor. A cooling fan driven by the inner rotor type brushless motor according to any one of claims 1 to 5.

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