JPS638704B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improved structure of a DC motor used for blowing air in a vehicle air conditioning system.

BACKGROUND ART Conventionally, air blowers used in air-conditioning and heating systems usually have a Sirotskov fan placed inside a casing, and a driving DC motor (motor) is usually mounted on the outside of the casing.
However, when an air conditioning system is used for a vehicle, there is a space limitation, so a flat motor is much more advantageous than a cylindrical shape because it will not protrude when attached to the side of the casing. For that reason,
Axial air gap type motors such as print motors and flat coreless motors are sometimes used as flat type motors, but these axial air gap type motors have an air gap formed in the axial direction that requires precision. It is difficult to manufacture the motor, and since the armature is disc-shaped, not only is it difficult to obtain a large space factor for the armature coil, but in order to increase the output, the outer diameter must be gradually increased. There was a drawback.

In order to solve the above-mentioned drawbacks, the present invention arranges the outer peripheral wall of a cup-shaped coreless armature to face the outer periphery of a magnet that forms four or more magnetic poles in the circumferential direction, and a brush on the inside of the coreless armature. By arranging the rotatable body and connecting the rotated body directly to the outer surface of the bottom wall of the armature, the air gap is arranged in the circumferential direction, making it easy to manufacture.Since the armature is cup-shaped, the armature coil can be easily manufactured. Not only can the space factor be increased, but output can be increased by simply increasing the height in the axial direction, making standardization of parts easy, and additional space is required for installing brushes. The object of the present invention is to provide a DC motor that is not only smaller in size but also capable of good heat dissipation from the armature by means of a rotating body directly connected to the outside of the armature. .

The present invention is an extension of the conventional cup-type coreless motor technology. Conventionally known cup-type coreless motors usually have a two-pole alnico magnet provided inside or outside of a long cylindrical cup armature, and a cylindrical commutator is disposed on the shaft on the outside of the cup armature. The present invention provides a flat type cup motor by changing the cup type coreless motor, which normally has a long cylindrical shape, to four or more poles, using a ferrite magnet as the field magnet, and improving the motor structure. .

The present invention will be explained below with reference to the drawings. 1 to 3 show a first embodiment of the motor of the present invention. 1 is a magnet in which four or more magnetic poles are formed at equal intervals in the circumferential direction, and is usually composed of arc-shaped ferrite magnets whose number corresponds to the number of poles (four in the figure). The magnet 1 is fixed by adhesive or the like to the outer peripheral surface of a cylindrical inner yoke 2 made of a soft iron plate such as SPCC. A cylindrical center piece 3 made of aluminum die-casting or resin molding is provided on the inner diameter side of the inner yoke 2, and this center piece 3 has bearing parts 4a, 4b which rotatably hold the shaft 14 in the center. It has oil supply felts 5 and 6, and furthermore, two brush holder parts 7 extending in the axial direction are provided at an interval of 90 degrees slightly on the outer peripheral side of the bearing part 4a. 8 and 9 are brushes and brush springs housed in the brush holder section 7. Several (three in the figure) protrusions 11 are integrally formed on the side surface of the center piece 3 opposite to the sliding surface of the brush 8.
The center piece 3 is fixed to the motor bracket 12 by press-fitting the center piece 3 into the motor bracket 12. Note that screws may be used instead of the protrusions 11. Reference numeral 13 designates a shallow cup-shaped coreless armature, which is made by molding an armature coil with heat-resistant resin and has a shaft 14 in the center of the cup, and a planar commutator 16 on the inner surface of the bottom wall 15a of the cup. is provided by molding, and the tip of the brush 8 mentioned above is configured to slide on this commutator 16. The cylindrical outer circumferential wall 15b of the cup is arranged to face the outer circumferential surface of the magnet 1 via an air gap. Also,
A plurality of (four in the figure) projections 17 for attaching a rotating body are integrally formed on the outer surface of the bottom wall 15a of the cup. 18 is an oil cutter provided on the end face of the bearing portion 4a, and 19 is a thrust stopper circlip fixed to the end face of the shaft 14. 20 is SPCE
It is fixed to the bracket 12 by a cylindrical external yoke made of a soft iron plate such as, for example, and its outer peripheral surface is placed opposite to the outer peripheral wall 15b of the cup via an air gap, and together with the magnet 1 and the inner yoke 2, a magnetic circuit is formed. It consists of 21 is bracket 12
23 is the end face of the shaft 14 and the bearing cover 21
This is a thrust receiving ball interposed between the Further, a plurality of hollow portions 24 penetrating in the axial direction are formed in a portion of the center piece 3 other than the portion where the brush holder portion 7 is formed, and a predetermined one of the hollow portions 24 is formed.
Bracket 1 at the part facing the two open ends
A ventilation hole 25 is formed in 2. Reference numeral 26 designates a plurality of jig insertion holes (four in the figure) provided in the bracket 12 in a portion facing each space formed between each magnet 1. , from the bracket 12 side, through each jig insertion hole 26 and the space formed between each magnet 1, the tips of a plurality of cylindrical rod-shaped jigs whose tips are aligned are brought into contact with the inner surface of the bottom wall 15a of the armature 13. After the armature 13 is held by these jigs, the rotating body is fixed by the protrusion 17, thereby preventing the armature 13 from deforming due to the force applied during this fixing. Reference numeral 27 indicates several mounting holes (three in the figure) formed on the outer circumferential side of the bracket 12 for mounting the motor to a case of an air-conditioning device or the like. 28 is a power cord for applying power supply voltage to the brush 8.

Next, the operation of the above configuration will be explained.
When a power supply voltage is applied to the power cord 28 from the power supply, this voltage is transmitted to the armature coil via the brush 8 and the commutator 16.
3 rotates. Here, if a blower member such as a blower or a fan is fixed by the protrusion 17 as a rotated body, the blower member rotates together with the armature 13, and as the blower member rotates, negative pressure is created on the outer wall side of the armature 13. , the ventilation holes 25, the hollow portion 24, the inner circumferential surface of the cup, and the outer circumferential surface of the cup, the armature 13 can be cooled by this air flow.
Further, the heat generated in the armature 13 is also dissipated through a rotating body directly connected to the armature 13.

FIG. 4 shows a second embodiment of the present invention, in which a blower 29 is connected to the armature 13 as a rotated body in contrast to the embodiment shown in FIG. This is a snap washer that is press-fitted into the protrusion 17 in order to connect it to the holder. The blower 29 may be connected by screw tightening instead of using the snap washer 30 and the protrusion 17. Also, if the outer diameter of the blower 29 is smaller than the outer diameter of the armature 13, the armature 13 and the cup of the blower 29 may be connected using resin. It is also possible to perform integral molding.

FIG. 5 shows a third embodiment of the present invention, in which a propeller fan 31 is connected to an armature 13 as a rotating body.
1 has a cup-shaped boss portion 32 disposed opposite to the outer circumferential surface of the external yoke 20 via an air gap, and between the boss portion 32 and the outer yoke 20, the outer circumferential surface of the external yoke 20 A labyrinth ring 33 having a U-shaped cross section fixed to the motor is disposed, and this labyrinth ring 33 has a waterproof function for the inside of the motor.

Note that the rotated body applied to the present invention is not limited to fans, blowers, etc., but may also be pulleys, gears, etc.

As described above, in the present invention, since the rotated body is directly connected to the outer surface of the bottom wall of the cup-shaped armature, heat dissipation from the armature can be improved through the rotated body, increasing the output of the motor. Not only can the output be increased by slightly increasing the axial length, but there is no need to increase the outer diameter, making it possible to standardize the motor. Therefore, it is easy to manufacture, and since the space factor of the armature coil can be high, low-cost ferrite magnets can be used.Furthermore, since the armature can be formed into a shallow cup-like shape, it has good vibration resistance. Since the brushes are arranged in the axial direction by utilizing the unnecessary space inside the inner yoke, there is no need for extra space for installing the brushes, which not only allows for more compact design, but also connects the rotated objects. This has the excellent effect that the brush does not get in the way.

Also, fix the centerpiece to the bracket,
In the form of cantilever support on this center piece,
The shaft is rotatably mounted, a cup-shaped armature is mounted on the shaft, and an external yoke integrated with the bracket is provided on the outer periphery of the armature, so the side of the armature opposite to the bracket can be left wide open. A special effect is that a sufficiently large fan can be attached to the section.

[Brief explanation of the drawing]

1 to 3 show a first embodiment of the electric motor of the present invention. FIG. 1 is a longitudinal sectional view taken along the line A-A' shown in FIG. 2, and FIG. A top view, and FIG. 3 is a left side view thereof. 4 and 5 are longitudinal sectional views showing second and third embodiments of the electric motor of the present invention. 1... Magnet, 2... Inner yoke, 4a,
4b...bearing part, 7...brush holder part, 8...
...Brush, 13... Armature, 15a... Bottom wall, 15b... Outer peripheral wall, 16... Commutator, 17...
...Protrusion for mounting the rotated body, 20...External yoke,
29, 31...Blower and propeller fan as rotating objects, 32...Boss portion, 33...Labyrinth ring.

Claims (1)

[Claims] 1. A ring-shaped inner yoke provided on the outer periphery of a cylindrical center piece forming a stator member, and a magnet fixed to the outer periphery of this inner yoke and forming four or more magnetic poles at equal intervals in the circumferential direction. A cup-shaped coreless armature in which a cylindrical outer circumferential wall is disposed opposite to the outer circumferential surface of the magnet via an air gap, and a shaft integrated with the armature for rotatably holding this armature. a bearing portion provided at the center portion of the center piece for cantilever support; a planar commutator provided on the inner bottom surface of the armature;
In the center piece inside the inner yoke, a brush holder part provided in the axial direction of the shaft, a brush housed in the brush holder part and having a tip in sliding contact with the commutator, and a brush holder part of the armature. A ring-shaped external yoke is arranged to face the outer circumferential surface of the armature via an air gap, and a mounting bracket is connected to the external yoke and connected to the end surface of the center piece opposite to the brush. A DC motor characterized by having a structure in which a rotating body consisting of a fan is directly connected.