KR20180113296A - Brush motor - Google Patents

Abstract

The present invention relates to a brush motor. The brush motor has a structure of 4-pole, 24-slot and 2-brush, and optimizes a pole ratio which is a ratio of magnet width to a pole interval, so as to minimize generation of a cogging torque and a ripple current due to a change in a magnetic field between a rotor and a stator while achieving miniaturization and lightening.

Description

Brush motor [0001]

More particularly, the present invention relates to a brush motor having a structure of a four pole, a twenty-second slot and a two brush, which can optimize the pole ratio as a ratio of the magnet width to pole spacing to enable miniaturization and weight reduction, To a vehicle brush motor capable of minimizing occurrence of cogging torque and ripple current due to a change in magnetic field between stator.

In recent years, interest in the environment and energy has been increasing worldwide in the automobile industry, and studies for improving fuel efficiency have been made. Research and development for lightening, miniaturization and high performance are continuously carried out in order to satisfy the needs of various consumers. In particular, in a vehicle air conditioning system, it is difficult to secure a sufficient space in the engine room. Therefore, the automotive air conditioner is required to be compact and capable of effectively controlling the temperature and the airflow.

Generally, a vehicle air conditioner is a device that can maintain the front and rear visibility of the driver by keeping the interior of the vehicle at a proper temperature in the summer or winter season, or by removing the property of being caught in the window of a car during rainy or winter season, Air is passed through the evaporator or the heater core through which cooling water flows to distribute the air in the cold or warm state to various directions in the vehicle interior through the ducts communicated with the respective parts of the vehicle interior .

Fig. 1 shows a front projection view of the vicinity of the blower unit 20 in the ordinary automotive air conditioner 50. Fig.

As shown in the drawing, a blower unit 20 for forcedly sucking the inside air or outside air of a vehicle and forcibly blowing air into a duct in the air conditioner is installed in the vehicle air conditioner 50.

An intake unit 10 is provided on the upstream side of the blower unit 20 and an intake unit 10 having an air conditioning filter 12 for filtering the air flowing through the intake air passage 11 is provided A blower fan 30 and a blower motor 40 are provided downstream of the blower unit 20 for supplying the air sucked through the intake passage 11 into the air conditioner.

Fig. 2 is a plan view of the motor used as the blower motor, and Fig. 3 is a waveform of the cogging torque of the motor.

The motor shown in Fig. 2 (a) is a bipolar, 12-slot motor, and the motor shown in Fig. 2 (b) is a 4-pole, 24-slot motor. 4-pole motor has much less weight and improves the package as compared with 2-pole motor. On the other hand, as shown in FIG. 3, quadrupole motor has larger cogging torque and unbalanced electromagnetic force than two-pole motor. Is generated.

Therefore, it is necessary to develop a technique capable of improving the disadvantages of the four-pole motor as described above.

Korean Patent Laid-Open Publication No. 2009-0040803 (entitled: Vehicle Blower Motor Assembly, Published Apr. 27, 2009)

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a four-pole, twenty-slot and two-brush structure that can be miniaturized and lightweight by optimizing pole ratio, And to provide a brush motor capable of minimizing generation of cogging torque and ripple current due to a change in magnetic field between a rotor and a stator.

A brush motor according to an embodiment of the present invention includes a rotor 100 having a plurality of slots 110 and installed on a rotary shaft 102; A commutator (200) installed on the rotating shaft (102) and disposed on one end side of the rotor (100); A brush 300 that contacts the commutator 200 to apply electricity; And at least one pair of N-pole and S-pole permanent magnets spaced at a predetermined distance in the radial direction from the rotor (100) and extending in the circumferential direction, wherein the ratio of the width of the magnet to the pole interval A stator 400 having a stiffness of 0.88 to 0.92; And a control unit.

More specifically, the stator 400 is formed such that the pole ratio satisfies the following equation (1).

[Formula 1]

0.88? L1 / R1? 0.92

Here, L1 is the length of one permanent magnet provided in the stator 400, and R1 is a length obtained by dividing the circumferential length of the circle formed by the face on which the permanent magnet is located, by the number n of permanent magnets.

At this time, the stator 400 may be arranged such that two permanent magnets of N poles and S poles are alternately arranged in the circumferential direction.

In addition, the rotor 100 has twenty-four slots 110, and two brushes 300 may be provided.

The stator 400 may have different thicknesses t in the width direction W corresponding to the circumferential direction of the rotor 100.

At this time, the stator 400 has a thickness t1 which is the thickest at the center portion of the width direction W corresponding to the circumferential direction of the rotor 100, and a thickness t2 which becomes gradually thinner toward the both edge portions ).

Preferably, the stator 400 has a thickness ratio of the center portion t1 and the both edge portions t2 of the width direction W corresponding to the circumferential direction of the rotor 100 to 10: 4 .

The vehicle DC motor according to the embodiment of the present invention has a structure of 4 poles, 24 slots and 2 brushes, so that even if the size of the coil and the stator of the rotor is reduced, the output equivalent to that of the conventional two- pole 12 slot 2 brush- And it is advantageous in that it can be downsized and lightened.

Particularly, the vehicle DC motor according to the embodiment of the present invention can optimize the pole ratio as a ratio of the magnet width to the pole interval, thereby making it possible to reduce the size and weight of the motor, as well as to reduce the cogging torque There is an advantage that the occurrence of ripple current can be minimized.

Further, since the cogging torque between the rotor and the stator can be reduced, the vibration of the rotor due to the cogging torque and the change in the rotation speed can be minimized, thereby improving the rotation performance of the motor .

Further, since the present invention has the structure of a 4 pole 24 slot 2 brush, the size of the coil portion and the stator of the rotor can be reduced without loss of rotation torque of the rotor, The current can be reduced.

Accordingly, the present invention has an effect of preventing generation of noise due to the ripple current and preventing damage to the battery and various electric devices.

Ultimately, when the present invention is applied to an air conditioner for a vehicle, the air conditioner can be downsized, slimmed, and lightweight by reducing the size and weight of the blower motor.

Brief Description of the Drawings Fig. 1 is a front projection view of a blower unit adjacent portion in a vehicle air conditioner. Fig.
2 is a plan view of the blower motor;
Fig. 3 is a waveform of the cogging torque of the motor shown in Fig. 2; Fig.
4 is a plan view of a brush motor according to an embodiment of the present invention.
5 is a graph showing the cogging torque according to the pole ratio in a DC motor having a 4-pole, 24-slot, and 2-brush structure.
6 is a graph showing an unbalanced electromagnetic force according to the pole ratio.
Fig. 7 is a table summarizing the cogging torque and the unbalanced electromagnetic force within the range of 0.88 to 0.92, respectively.
8 is a perspective view illustrating a stator of a brush motor according to an embodiment of the present invention.

Hereinafter, a brush motor according to the present invention as described above will be described in detail with reference to the accompanying drawings.

4, the brush motor according to the embodiment of the present invention includes a rotor 100, a commutator 200, a brush 300, and a stator 400. And further includes a motor housing 101 basically.

The brush motor has a structure in which stator 400 is installed at a predetermined interval in a substantially cylindrical motor housing 101 and a rotor 100 is rotatably installed inside the stator 400 do.

More specifically, the rotor 100 has a plurality of slots 110 and is installed in the axially extending rotary shaft 102. In particular, the plurality of slots 110 are formed at intervals along the circumferential direction of the rotor 100, and the coil 120 is wound.

The commutator 200 is installed on the rotary shaft 102 and is disposed on one end side of the rotor 100.

The brush motor includes a brush 300 installed from the motor housing 101 toward the commutator 200 of the rotor 100. The brush 300 is frictionally connected to the commutator 200 of the rotor 100, Electricity is intermittently supplied to each commutator 200 of the rotor 100 while being in contact with each other.

4, the brush 300 is fixedly mounted on the inner circumferential surface of the motor housing 101 corresponding to the commutators 200, and the motor housing 101 corresponding to the commutators 200 And may be installed at an interval of 90 degrees on the inner circumferential surface of the motor housing 101.

The brush 300 is configured to frictionally contact at least two commutators 200 at the same time and the brush 300 configured as described above is configured to apply electricity to at least two commutators 200 per unit do.

Meanwhile, when electricity is applied to the commutator 200 through the brush 300, the brush motors excite and deenergize the coils 120 of the rotor by the applied electric power, and the external stator 400 And the rotor 100 is rotated while the rotating torque is generated by the attraction force and the repulsive force with the stator 400.

4, the stator 400 includes at least one pair of N and S pole permanent magnets spaced apart from the rotor 100 by a predetermined distance in the radial direction and extending in the circumferential direction , A quadrupole motor in which two N poles and two S poles are alternately disposed in the circumferential direction can be proposed in the preferred embodiment of the present invention.

In addition, the brush motor may have twenty-four slots 110 and a plurality of commutators 200, respectively. The rotor 100 having such a configuration has 24 individual pieces of the commutator 200 and the slots 110 so that the coil 120 wound around the slot 110 also has 24 individual structures, And a 4-pole, 24-slot (Slot) 2 brush (Brush) having 24 slots (110).

Particularly, the brush motor of the present invention is characterized in that the pole ratio is 0.88 to 0.92, which means the ratio of the magnet width to pole spacing.

At this time, the pole ratio of the stator 400 can be defined by the following equation (1).

[Formula 1]

0.88? L1 / R1? 0.92

Here, L1 denotes a length of one permanent magnet provided in the stator 400, and R1 denotes a length obtained by dividing the circumferential length of the circle formed by the surface on which the permanent magnet is located, by the number n of permanent magnets.

FIG. 5 is a graph showing the cogging torque according to the pole ratio in the DC motor having the four pole, 24 slot (110), and two brush (300) structures, and FIG. 6 is a graph analyzing the unbalanced electromagnetic force according to the pole ratio. FIG. 7 is a table summarizing the cogging torque and the unbalanced electromagnetic force within the range of 0.88 to 0.92 in terms of pole ratio.

As shown in Figs. 5 and 7, even though the DC motor having the four poles, the twenty-four slots (110), and the two brushes (300) structure has the same structure, the characteristics of the cogging torque and the unbalanced electromagnetic force Therefore, it is desirable that the pole ratio is designed within the range of 0.88 to 0.92 so that cogging torque and unbalanced electromagnetic force can be minimized.

For example, in the case of a DC motor having four poles, 24 slots (110) and two brushes (300) as described above, if the radius of the circle formed by the permanent magnets is 5 cm, then R1 satisfies (2π * 5) /4=7.85 cm, it is preferable that the length L1 of one permanent magnet is designed within 6.908 cm? L1? 7.222 cm.

Accordingly, the number of the slots 110, the coils 120, and the number of the stator 400 corresponding to the slot 110, the number of the coils 120, and the number of the coils 120 is increased in the brush motor of the four- The attracting force and the repulsive force generated between the coil 120 and the stator 400 of the rotor 100 and the rotating force caused by the rotation of the stator 400 The torque can be increased.

In particular, although the brush motor reduces the size of the coil 120 of the rotor 100 and the size of the stator 400, the brush motor has an output equal to that of the blower motor having the structure of the bipolar 12 slot (110) 2 brush 300 It becomes possible to reduce the size and weight.

The brush motor can significantly reduce the cogging torque generated between the coil 120 and the stator 400 due to the reduced size of the coil 120 of the rotor 100 and the size of the stator 400. [ In particular, the cogging torque of the 2 pole 12 slot (110) 2 brush (300) type DC motor can be remarkably reduced.

As a result, the brush motor can remarkably reduce the vibration of the rotor 100 caused by the cogging torque and the change in the rotation speed of the rotor 100, thereby improving the rotation performance of the motor .

Because of the size of the coils 120 and the stator 400 of the reduced rotor 100, the brush motor is affected by a change in attraction between the coils 120 and the stator 400, The generated ripple current can be remarkably reduced.

Particularly, in order to increase the rotation speed of the blower, the amplitude of the ripple current can be remarkably reduced even if the voltage applied to the motor is increased.

8, the brush motor of the present invention includes a plurality of stator 400 installed around a rotor 100, and each of the stator 400 includes a rotor 100, (T) corresponding to the width direction (W) corresponding to the circumferential direction of the substrate (1).

Particularly, the stator 400 may be configured to have a thickness t2 in which the thickness t1 of the center portion is the thickest and the thickness t2 of the stator 400 becomes gradually thinner toward the both edge portions.

Preferably, the stator 400 has a thickness ratio of 10: 4 between the center portion and the both edge portions of the width direction W portion.

The stator 400 having such a structure has a structure in which the middle portion is thick and the thickness becomes gradually thinner toward the both edge portions, so that the magnetic force in the middle portion increases and the magnetic force decreases toward both edge portions.

The rotation torque of the rotor 100 due to the attractive force between the coil 120 of the rotor 100 and the stator 400 and the repulsive force during rotation of the rotor 100 is not lost, The cogging torque and the ripple current generated due to the attraction change between the coil 120 portion of the stator 400 and the boundary portion of the stator 400 can be reduced.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. It goes without saying that various modifications can be made.

100: rotor
101: motor housing 102:
110: slot 120: coil
200: commutator
300: Brush
400: stator

Claims (8)

A rotor (100) having a plurality of slots (110) and provided on a rotating shaft (102);
A commutator (200) installed on the rotating shaft (102) and disposed on one end side of the rotor (100);
A brush 300 that contacts the commutator 200 to apply electricity; And
At least one pair of N and S pole permanent magnets spaced apart in the radial direction from the rotor 100 and extending in the circumferential direction, wherein the ratio of the magnet width to the pole interval is 0.88 A stator 400 of about 0.92; And the brush motor.
The method according to claim 1,
The stator 400 has
Wherein the pole ratio is formed so as to satisfy the following expression (1).
[Formula 1]
0.88? L1 / R1? 0.92
Here, L1 is the length of one permanent magnet provided in the stator 400, and R1 is a length obtained by dividing the circumferential length of the circle formed by the face on which the permanent magnet is located, by the number n of permanent magnets.
The method according to claim 1,
The stator 400 has
And two permanent magnets of N poles and S poles are alternately arranged in the circumferential direction.
The method of claim 3,
The rotor (100)
And the slots (110) are twenty-four.
5. The method of claim 4,
The brush (300)
Wherein the brush motor is provided with two brush motors.
The method of claim 3,
The stator 400 has
Has a different thickness (t) according to a width direction (W) corresponding to a circumferential direction of the rotor (100).
The method according to claim 6,
The stator 400 has
The thickness t2 of the middle portion of the width direction W corresponding to the circumferential direction of the rotor 100 is the largest and the thickness t2 is gradually thinner toward the both edge portions. motor.
8. The method of claim 7,
The stator 400 has
Wherein a thickness ratio of a middle portion (t1) to both edge portions (t2) in the width direction (W) corresponding to the circumferential direction of the rotor (100) is 10: 4.

Images