JP7103103B2 - Fan motor - Google Patents

Description

The present invention relates to a fan motor.

Conventionally, a fan motor including a fan and a motor body has been used. The motor body used for the fan motor is generally a brushless motor (see, for example, Patent Document 1). The brushless motor includes a stator, a shaft, and a rotor. The rotor has a rotor housing, and a shaft is inserted inside the bearing accommodating portion formed in the rotor housing. A pair of ball bearings are housed inside the bearing accommodating portion, and the rotor is rotatably supported by the shaft via the pair of ball bearings.

Japanese Patent No. 6220666

4 and 5 show the structure of a pair of ball bearings applied to the above-mentioned fan motor and its peripheral portion. In this structure, a first ball bearing 102 and a second ball bearing 104 are used as a pair of ball bearings. In FIGS. 4 and 5, the arrow A1 indicates one side of each member in the axial direction, and the arrow A2 indicates the other side of each member in the axial direction. The second ball bearing 104 is arranged on the arrow A1 side of the first ball bearing 102.

A shaft 106 is loosely inserted (inserted with play) inside the first inner ring 102A of the first ball bearing 102 and the second inner ring 104A of the second ball bearing 104, and the first ball bearing 102 The first outer ring 102B and the second outer ring 104B of the second ball bearing 104 are press-fitted inside the bearing accommodating portion 110 formed in the rotor housing 108. In FIGS. 4 and 5, the press-fitting state of the first outer ring 102B and the second outer ring 104B to the inside of the bearing accommodating portion 110 is shown by a thick solid line L1, and the shaft 106 to the inside of the first inner ring 102A and the second inner ring 104A. The idle state of is indicated by a thick broken line L2.

A spring 112 is arranged on the arrow A2 side of the first inner ring 102A, and a preload P is applied to the first inner ring 102A on the arrow A1 side by the spring 112. A C ring 114 fixed to the shaft 106 is arranged on the arrow A1 side of the second inner ring 104A, and the second inner ring 104A is supported by the C ring 114 from the arrow A1 side.

At the end of the bearing accommodating portion 110 on the arrow A2 side, a bent portion 116 bent toward the inside of the bearing accommodating portion 110 is formed, and the first outer ring 102B is an annular plate from the arrow A2 side. It is supported by the bend 116 via 118. A cylindrical collar 120 is interposed between the first outer ring 102B and the second outer ring 104B, and the second outer ring 104B is an annular shape that is caulked and fixed to the end of the bearing accommodating portion 110 on the arrow A1 side. It is supported from the arrow A1 side by the stopper 122 of.

By the way, the fan motor having the structure shown in FIGS. 4 and 5 may be used together with the rotor 124 so that the fan 126 rotates in the forward direction or in the reverse direction. FIG. 4 shows a state in which the fan 126 is rotating forward together with the rotor 124, and FIG. 5 shows a state in which the fan 126 is rotating in the reverse direction together with the rotor 124. That is, the case where the thrust F1 to the arrow A1 side acts on the fan 126 is the forward rotation, and the case where the thrust F2 to the arrow A2 side acts on the fan 126 is the reverse rotation.

As shown in FIG. 4, when the fan 126 rotates in the forward direction together with the rotor 124, the thrust F1 on the arrow A1 side acting on the fan 126 and the preload P on the arrow A1 side applied by the spring 112 are the same. Turn around. However, as shown in FIG. 5, when the fan 126 rotates in the reverse direction together with the rotor 124, the thrust F2 on the arrow A2 side acting on the fan 126 and the preload P on the arrow A1 side applied by the spring 112. Is reversed and the spring 112 is compressed.

When the fan 126 rotates in the reverse direction together with the rotor 124 in this way, as shown by the arrow A in FIG. 4, the first inner ring 102A and the second inner ring 104A are in axially sliding contact with the shaft 106, and the shaft 106 Problems such as the surface being worn or the fan 126 moving toward the arrow A2 and the fan 126 interfering with a shroud (not shown) may occur.

Here, in order to prevent the above-mentioned trouble from occurring, it is conceivable to increase the elastic force of the spring 112. However, in this case, it is necessary to increase the axial and radial dimensions of the spring 112, which leads to an increase in the size of the fan motor.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a fan motor capable of suppressing wear on the surface of a shaft and interference between a fan and a shroud while suppressing an increase in size.

In order to solve the above problems, the fan motor according to claim 1 includes a stator, a shaft arranged on the central axis of the stator, and a bearing accommodating formed in a tubular shape and having the shaft inserted inside. A rotor having a portion, a fan mounted on the rotor having a lid portion arranged on one side in the axial direction of the bearing accommodating portion, a first inner ring into which the shaft is press-fitted inside, and the bearing accommodating portion. It has a first ball bearing having a first outer ring press-fitted inside the portion, a second inner ring having the shaft press-fitted inside, and a second outer ring loosely inserted inside the bearing accommodating portion. A second ball bearing arranged on one side in the axial direction of the first ball bearing, and a grommet having elasticity and interposing in a compressed state between the lid and the second outer ring are provided.

According to this fan motor, shafts are press-fitted inside the first inner ring of the first ball bearing and the second inner ring of the second ball bearing, respectively. Therefore, since it is possible to prevent the first inner ring and the second inner ring from sliding in contact with the shaft in the axial direction, it is possible to suppress wear on the surface of the shaft.

Further, the fan has a lid portion arranged on one side in the axial direction of the bearing accommodating portion, and a grommet is provided between the lid portion and the second outer ring loosely inserted inside the bearing accommodating portion. It intervenes in a compressed state. Therefore, a preload to the other side in the axial direction can be applied to the second outer ring.

Here, when the fan rotates in the reverse direction together with the rotor, the thrust acting on the fan on the other side in the axial direction and the preload applied to the second outer ring by the grommet on the other side in the axial direction are in the same direction. .. Therefore, the second outer ring loosely inserted inside the bearing accommodating portion moves to the other side in the axial direction.

However, a shaft is press-fitted inside the second inner ring that constitutes the second ball bearing together with the second outer ring. Therefore, the movement of the second outer ring is restricted, and a binding force acts on the fan in one axial direction. As a result, the movement of the fan to the other side in the axial direction can be suppressed, so that the fan can be suppressed from interfering with the shroud.

Moreover, since it is not necessary to increase the elastic force of the grommet and it is not necessary to increase the axial and radial dimensions of the grommet, it is possible to suppress the increase in size of the fan motor.

It is a vertical sectional view of the fan motor which concerns on one Embodiment of this invention. It is an enlarged view of the 1st ball bearing and the 2nd ball bearing of FIG. 1 and the peripheral part thereof, and is the figure which shows the state which the fan rotates forward together with the rotor. It is an enlarged view of the 1st ball bearing, the 2nd ball bearing and the peripheral part thereof of FIG. 1, and is the figure which shows the state which the fan rotates in the reverse direction together with a rotor. It is an enlarged view of a pair of ball bearings applied to a conventional fan motor and the peripheral part thereof, and is the figure which shows the state which a fan is rotating forward together with a rotor. It is an enlarged view of a pair of ball bearings applied to a conventional fan motor and the peripheral part thereof, and is the figure which shows the state which the fan rotates in the reverse direction together with a rotor.

Hereinafter, an embodiment of the present invention will be described.

As shown in FIG. 1, the fan motor 10 according to the embodiment of the present invention includes a fan 12 and a motor main body 14. In each figure, the arrow A1 indicates one side of the motor body 14 in the axial direction, and the arrow A2 indicates the other side of the motor body 14 in the axial direction. The motor body 14 is a brushless motor, and includes a stator 16, a shaft 18, a rotor 20, a center piece 22, a circuit board 24, a connector member 26, a board case 28, and the like.

The stator 16 includes a stator core 32 and a plurality of windings 34. The stator core 32 has an annular portion 36 and a plurality of teeth portions 38 formed radially around the annular portion 36. The winding 34 is wound around the teeth portion 38. The shaft 18 is inserted inside the annular portion 36 together with the bearing accommodating portion 44 described later, and is arranged on the central axis of the stator 16.

The rotor 20 includes a rotor housing 40 and a rotor magnet 42. The rotor housing 40 has a cylindrical bearing accommodating portion 44 and a bottomed tubular outer cylinder portion 46. A rotor magnet 42 is fixed to the inner peripheral surface of the outer cylinder portion 46. A bottom wall portion 48 is formed on the arrow A1 side of the outer cylinder portion 46, and the arrow A2 side of the outer cylinder portion 46 is open.

The bearing accommodating portion 44 extends from the central portion of the bottom wall portion 48 toward the arrow A2 side. A shaft 18 is inserted inside the bearing accommodating portion 44. Further, a first ball bearing 52 and a second ball bearing 54 are housed inside the bearing housing portion 44. The first ball bearing 52 and the second ball bearing 54 are arranged between the shaft 18 and the bearing accommodating portion 44, and rotatably support the rotor 20 with respect to the shaft 18. The arrow A2 side of the shaft 18 projects from the bearing accommodating portion 44 toward the center piece 22, which will be described later, through the opening on the arrow A2 side of the bearing accommodating portion 44.

The center piece 22 has a flat plate-shaped main body portion 62. The main body 62 is arranged so as to face the opening of the outer cylinder 46. A concave shaft support portion 64 that opens to the arrow A1 side is formed in the central portion of the main body portion 62, and the shaft 18 is press-fitted into the shaft support portion 64. Further, the above-mentioned stator core 32 is fixed to the main body 62 by a screw 66.

The circuit board 24 is fixed to the side of the main body 62 opposite to the stator core 32. An electronic circuit for switching the energization of the plurality of windings 34 is formed on the circuit board 24. The connector member 26 is provided corresponding to a part of the peripheral edge portion of the main body portion 62. The connector member 26 is provided with a connector portion 72 protruding outward from the main body portion 62, and the connector terminal provided on the connector portion 72 is electrically connected to an electronic circuit formed on the circuit board 24. It is connected.

The substrate case 28 is formed in a flat box shape, and is assembled to the main body portion 62 from the side opposite to the stator core 32 with respect to the main body portion 62. The circuit board 24 is housed in the space between the board case 28 and the main body 62.

The fan 12 has a mounting portion 82 provided at the center of the fan 12 and a plurality of blades 84 provided around the mounting portion 82. The mounting portion 82 is formed in a bottomed cylindrical shape like the rotor housing 40, and is mounted on the rotor housing 40 in a state of covering the rotor housing 40.

Then, in the fan motor 10, when the energization of the plurality of windings 34 is switched by the electronic circuit formed on the circuit board 24, a rotating magnetic field is formed in the stator 16 and between the rotating magnetic field and the rotor magnet 42. The rotor 20 is rotated by the suction and repulsive force acting on the rotor 20. Further, in the fan motor 10, the direction of the rotating magnetic field formed on the stator 16 can be changed, so that the fan 12 can be rotated forward and reverse together with the rotor 20.

Subsequently, with reference to FIGS. 2 and 3, the structures of the first ball bearing 52 and the second ball bearing 54 of FIG. 1 and their peripheral portions will be described in more detail.

2 and 3 are enlarged views of the first ball bearing 52 and the second ball bearing 54 of FIG. 1 and their peripheral portions. FIG. 2 shows a state in which the fan 12 is rotating forward together with the rotor 20, and FIG. 3 shows a state in which the fan 12 is rotating in the reverse direction together with the rotor 20. That is, the case where the thrust F1 toward the arrow A1 acts on the fan 12 is the forward rotation, and the case where the thrust F2 toward the arrow A2 acts on the fan 12 is the reverse rotation. A shroud (not shown) is provided around the fan 12 (see also FIG. 1). This shroud includes a portion of the fan 12 located on the arrow A2 side.

The second ball bearing 54 is arranged on the arrow A1 side of the first ball bearing 52. A gap is provided between the first ball bearing 52 and the second ball bearing 54. The first ball bearing 52 has a first inner ring 52A and a first outer ring 52B. Similarly, the second ball bearing 54 has a second inner ring 54A and a second outer ring 54B.

A shaft 18 is press-fitted inside the first inner ring 52A and the second inner ring 54A, respectively. Further, the first outer ring 52B is press-fitted inside the bearing accommodating portion 44. In FIGS. 2 and 3, the press-fitting state of the shaft 18 inside the first inner ring 52A and the second inner ring 54A and the press-fitting state of the first outer ring 52B inside the bearing accommodating portion 44 are shown by a thick solid line L1. ing. On the other hand, the second outer ring 54B is loosely inserted (inserted with play) inside the bearing accommodating portion 44. In FIGS. 2 and 3, the loosely inserted state of the second outer ring 54B inward of the bearing accommodating portion 44 is indicated by a thick broken line L2.

In the present embodiment, by providing the bearing accommodating portion 44 with a minute step (not shown), the portion corresponding to the second outer ring 54B in the bearing accommodating portion 44 is more than the portion corresponding to the first outer ring 52B in the bearing accommodating portion 44. The inner diameter is larger. As a result, the first outer ring 52B is press-fitted inside the bearing accommodating portion 44, and the second outer ring 54B is loosely inserted inside the bearing accommodating portion 44.

The central portion of the bottom wall portion 88 of the bottomed tubular mounting portion 82 formed on the fan 12 is formed as a lid portion 92 that closes the opening on the arrow A1 side of the bearing accommodating portion 44. An annular grommet 94 is arranged between the second outer ring 54B and the second outer ring 54B. The grommet 94 has elasticity because it is formed of, for example, rubber, and is interposed between the lid portion 92 and the second outer ring 54B in a compressed state. The grommet 94 applies a preload P to the arrow A2 side to the second outer ring 54B.

According to the fan motor 10, the shaft 18 is press-fitted inside the first inner ring 52A of the first ball bearing 52 and the second inner ring 54A of the second ball bearing 54, respectively. Therefore, since it is possible to prevent the first inner ring 52A and the second inner ring 54A from sliding in contact with the shaft 18 in the axial direction, it is possible to suppress wear on the surface of the shaft 18.

Further, the fan 12 has a lid portion 92 arranged on the arrow A1 side of the bearing accommodating portion 44, and a grommet 94 is interposed between the lid portion 92 and the second outer ring 54B in a compressed state. ing. Therefore, the preload P to the arrow A2 side can be applied to the second outer ring 54B.

Here, as shown in FIG. 3, when the fan 12 rotates in the reverse direction together with the rotor 20, the thrust F2 toward the arrow A2 acting on the fan 12 and the grommet 94 are applied to the second outer ring 54B. The preload P to the arrow A2 side is in the same direction. Therefore, the second outer ring 54B loosely inserted inside the bearing accommodating portion 44 moves to the arrow A2 side.

However, the shaft 18 is press-fitted inside the second inner ring 54A that constitutes the second ball bearing 54 together with the second outer ring 54B. Therefore, the movement of the second outer ring 54B is restricted, and a binding force toward the arrow A1 acts on the fan 12. As a result, the movement of the fan 12 toward the arrow A2 side can be suppressed, so that the fan 12 can be prevented from interfering with a shroud (not shown). As a result, the fan motor 10 can be used in both the case where the fan 12 is rotated forward and the case where the fan 12 is rotated in the reverse direction together with the rotor 20, so that the degree of freedom in using the fan 12 can be improved.

Moreover, since it is not necessary to increase the elastic force of the grommet 94 and it is not necessary to increase the axial and radial dimensions of the grommet 94, it is possible to suppress the increase in size of the fan motor 10.

Although one embodiment of the present invention has been described above, the present invention is not limited to the above, and it goes without saying that the present invention can be variously modified and implemented within a range not deviating from the gist thereof. Is.

10 ... fan motor, 12 ... fan, 14 ... motor body, 16 ... stator, 18 ... shaft, 20 ... rotor, 22 ... center piece, 24 ... circuit board, 26 ... connector member, 28 ... board case, 30 ... stator core, 32 ... insulator, 34 ... winding, 36 ... annular part, 38 ... teeth part, 40 ... rotor housing, 42 ... rotor magnet, 44 ... bearing housing part, 46 ... outer cylinder part, 48 ... bottom wall part, 52 ... th One ball bearing, 52A ... first inner ring, 52B ... first outer ring, 54 ... second ball bearing, 54A ... second inner ring, 54B ... second outer ring, 62 ... main body, 64 ... shaft support, 66 ... screw, 72 ... Connector part, 82 ... Mounting part, 84 ... Blade, 86 ... Outer cylinder part, 88 ... Bottom wall part, 92 ... Lid part, 94 ... Glomet

Claims (1)

With the stator
A shaft arranged on the central axis of the stator and
A rotor having a bearing accommodating portion formed in a cylindrical shape and having the shaft inserted inside,
A fan mounted on the rotor and having a lid portion arranged on one side in the axial direction of the bearing accommodating portion.
A first ball bearing having a first inner ring in which the shaft is press-fitted inside and a first outer ring in which the shaft is press-fitted inside the bearing accommodating portion.
A second ball bearing having a second inner ring into which the shaft is press-fitted inside and a second outer ring loosely inserted inside the bearing accommodating portion, which is arranged on one side in the axial direction of the first ball bearing. When,
An elastic grommet that is interposed between the lid and the second outer ring in a compressed state.
A fan motor equipped with.

Images