KR102196317B1 - Fan motor and bearings - Google Patents

Abstract

According to the present invention, provided are a pre-pressure method and a structure. A bearing assembly includes: a shaft forming a rotation axis; a center part protruding from the shaft in a radial direction of the rotation axis; a first bearing provided in an upper part of the center part, and including outer and inner wheels; a second bearing provided adjacently to a lower side of the center part, and including outer and inner wheels; a bracket pressing the outer wheel of the first bearing and the outer wheel of the second bearing into the inner circumference surface and fixing the same, and penetrated by the shaft; and a fixing member provided in an upper part of the first bearing, and combined with the shaft to movable in an axial direction. As the fixing member is moved toward the center part, the fixing member applies a load to the inner wheel of the first bearing to prepress the bearings. Therefore, bearings in a fan motor aiming at miniaturization and lightening can have a more advantageous load support direction.

Description

Fan motor and bearings

The present invention relates to a fan motor in which a motor and a fan are integrally installed, and more particularly, to a structure of a bearing supporting a rotating shaft of a fan motor rotating at an ultra high speed.

The fan motor integrally comprises a motor providing rotational force and a fan rotating by the motor to generate airflow. Fan motors are widely used in home appliances that require airflow, and a typical example is a vacuum cleaner.

The vacuum cleaner may be of a type provided with a main body in which a fan motor is installed and a suction duct in which a suction port is installed separately. In addition, the vacuum cleaner may be of a handy type in which a fan motor is integrally installed on the suction duct side.

In particular, in the case of the handy type in which the fan motor is integrally installed on the suction duct side, there is a problem that the suction power of the vacuum cleaner is deteriorated due to low output.

Accordingly, attempts to increase the output of the fan motor while reducing the size and weight of the fan motor are continuing. Higher fan motor output means that high-speed rotation is absolutely necessary. High-speed rotation causes noise, vibration, and heat generation problems.

Consequently, it is necessary to design a bearing capable of supporting a rotating shaft rotating at high speed.

There may be several types of bearings that support a rotating shaft rotating at high speed, but rolling bearings and air bearings are typical examples.

Rolling bearings are bearings that reduce friction by placing a ball and a roller between the outer ring and the inner ring to make rotational contact. In addition, it is divided into ball bearings and roller bearings according to the type of rolling element.

Air bearings include a static pressure bearing that uses a static pressure given from the outside, and a dynamic pressure bearing that uses a hydrodynamic pressure caused by the viscosity of a gas caused by rotation of a shaft. Air bearings are advantageous for high-speed rotation in that rotation is made particularly slippery. In addition, it can be used at both high and low temperatures, so it is suitable for heat generation due to high speed rotation.

In particular, in the case of rolling bearings, as the rotational speed of the rotating shaft provided in the fan motor for miniaturization and weight reduction is increased, the outer ring to be fixed to the bracket is greatly affected by the rotation of the inner ring, causing the phenomenon to rotate together. I can. When the outer ring of the bearing rotates together, the bearing may be deformed, damaged, or damaged, which may greatly reduce the reliability of the bearing.

Accordingly, a method of bonding between the outer ring and the bearing support can be proposed, but in this method, the phenomenon of deformation and solidification as the liquid adhesive is hardened may cause a problem in which the outer ring of the rolling bearing is deformed or the alignment of the outer ring is disturbed. have.

In addition, heat generated by rotating at high speed may extend the rotation shaft in the longitudinal direction, and accordingly, the position of the inner ring may also be displaced along the longitudinal direction of the shaft. At this time, if the outer ring is firmly fixed to the bearing support by bonding, the outer ring and the inner ring may not be displaced together. Consequently, the difference in displacement between the inner ring and the outer ring causes stress on the rolling member and shortening the life of the rolling bearing.

Accordingly, an object of the present invention is to provide a preload method and structure of a ball bearing stably supporting a rotating shaft by fixing and preloading a bearing in a bracket to more advantageously receive a load caused by high-speed rotation.

In order to achieve the above object, the present invention comprises: a shaft forming a rotating shaft; A central portion protruding from the shaft in a radial direction of the rotation shaft; A first bearing provided on the upper portion of the center and including an outer ring and an inner ring; A second bearing provided in contact with a lower surface of the center and including an outer ring and an inner ring; A bracket in which the outer ring of the first bearing and the outer ring of the second bearing are press-fitted to the inner circumferential surface, and the shaft is provided through it; And a fixing member provided on an upper portion of the first bearing and coupled to the shaft and movable along an axial direction, wherein the fixing member is moved toward the center of the first bearing. It is possible to provide a bearing assembly, characterized in that the preload of the bearing is performed by applying a load to the inner ring of.

In addition, an embodiment of the present invention is characterized in that the first bearing further includes a rolling member provided between the outer ring and the inner ring, and the second bearing further comprises a rolling member provided between the outer ring and the inner ring. A bearing assembly can be provided.

In an embodiment of the present invention, the bracket includes a stepped portion extending toward the shaft at an upper end, and the outer ring of the first bearing is press-fitted to an upper end of the inner circumferential surface of the bracket, so that the lower surface of the stepped portion and the first It is possible to provide a bearing assembly characterized in that the upper surface of the bearing is in contact.

In addition, an embodiment of the present invention may provide a bearing assembly, wherein the shaft is provided with a thread on the upper portion of the center, and the fixing member is a nut having a fastening portion corresponding to the thread on an inner circumferential surface. .

In addition, in an embodiment of the present invention, the shaft includes a plurality of fastening holes provided at an upper portion of the center and formed at equal intervals along the outer circumferential surface of the shaft, and the plurality of fastening holes are each inclined downward. It is provided, and the fixing member can provide a bearing assembly, characterized in that the bolt corresponding to the fastening hole.

In addition, an embodiment of the present invention is a shaft forming a rotating shaft; A central portion protruding from the shaft in a radial direction of the rotation shaft; An impeller rotatably coupled to the shaft; A first bearing located under the impeller and supporting the rotation of the shaft, provided at an upper portion of the center and including an outer ring and an inner ring; and a second bearing provided in contact with the lower surface of the center and including an outer ring and an inner ring A rolling bearing comprising; A bracket in which the outer ring of the first bearing and the outer ring of the second bearing are press-fitted to the inner circumferential surface, and the shaft is provided through it; A fixing member provided on an upper portion of the first bearing and coupled with the shaft to move along an axial direction; A rotor positioned under the rolling bearing and rotatably coupled to the shaft; A stator surrounding the outside of the rotor; And an air bearing positioned below the rotor and the stator and supporting the rotation of the shaft, wherein the fixing member loads the inner ring of the first bearing as the fixing member moves toward the center. It is possible to provide a fan motor, characterized in that the preload of the rolling bearing is performed by applying a.

In an embodiment of the present invention, the bracket includes a stepped portion extending toward the shaft at an upper end, and the outer ring of the first bearing is press-fitted to an upper end of the inner circumferential surface of the bracket, so that the lower surface of the stepped portion and the first It is possible to provide a fan motor characterized in that the upper surface of the bearing is in contact.

In addition, an embodiment of the present invention may provide a fan motor, wherein the shaft is provided with a screw thread in the upper portion of the center, and the fixing member is a nut having a fastening portion corresponding to the screw thread on an inner circumferential surface. .

In addition, in an embodiment of the present invention, the shaft includes a plurality of fastening holes provided at an upper portion of the center and formed at equal intervals along the outer circumferential surface of the shaft, and the plurality of fastening holes are each inclined downward. The fan motor may be provided, and the fixing member is a bolt corresponding to the fastening hole.

In addition, an embodiment of the present invention is a shaft; A central portion protruding from the shaft in a radial direction of the rotation shaft; A first bearing including an outer ring and an inner ring; A second bearing including an outer ring and an inner ring; A bracket through which the shaft is provided and includes a stepped portion extending toward the shaft at an upper end; And a fixing member movable along the axial direction, wherein the outer ring of the first bearing is press-fitted in contact with the inner peripheral surface of the bracket and the lower surface of the stepped portion, and the inner ring of the second bearing is fixed. Press-fitting and fixing the shaft in contact with the lower surface of the center; Sliding the shaft through the inner rings of the first bearing; Coupling the fixing member to the shaft so as to be positioned above the first bearing; A method of preloading a bearing assembly, comprising preloading the bearing, including moving the fixing member downward in an axial direction.

According to an embodiment of the present invention, it is possible to apply a preload to the bearing in an arrangement advantageous for supporting the load.

According to an embodiment of the present invention, there is no bonding process during the preloading process of the bearing, and thus advantageous effects may occur in terms of assembly.

According to an embodiment of the present invention, the preload degree may be adjusted according to the moving degree of the fixing member.

1 is a view showing a cross section of a fan motor,
FIG. 2 is an enlarged view of the air bearing in FIG. 1;
3 is an exploded perspective view of a fan motor;
4 is a view showing an air bearing to which a snap ring can be coupled;
5 is a view showing a snap ring,
6 is a view showing an exploded perspective view of a fan motor to which a snap ring can be coupled;
7 is a view showing a cross section of a bearing preloaded through an elastic member;
8 is a view showing a cross section of a bearing preloaded through an elastic member;
9 is a view showing a cross section of a bearing according to a preferred embodiment of the present invention,
10 is a view showing a cross-section of a bearing according to another embodiment of the present invention.

Hereinafter, a conventional drawing for understanding the present invention capable of realizing the above object will be described with reference to the accompanying drawings and a preferred embodiment of the present invention.

In this process, the size or shape of the components shown in the drawings may be exaggerated for clarity and convenience of description. In addition, terms specifically defined in consideration of the configuration and operation of the present invention may vary according to the intention or custom of users or operators.

Meanwhile, in the present invention, terms such as first and/or second may be used to describe various components, but the components are not limited to the terms. The terms are only for the purpose of distinguishing one component from other components, for example, within a range not departing from the scope of the rights according to the concept of the present invention, the first component may be referred to as the second component, Similarly, the second component may also be referred to as a first component.

Definitions of these terms should be made based on the contents throughout the present specification.

1 is a view showing a cross-section of a fan motor, and FIG. 2 is an enlarged view of the air bearing 60 shown in FIG. 1.

1 to 2, the fan motor 1 includes a shaft 10, an impeller 20, a rolling bearing 30, a rotor 40, a stator 50, and an air bearing 60. It may include.

The shaft 10 may rotate by receiving power by a rotor 40 and a stator 50 to be described later. Accordingly, the shaft 10 may form a rotation shaft, and the impeller 20 to be described later may be coupled to the shaft 10 to rotate together with the shaft 10.

The impeller 20 may include a hub 21 and a plurality of blades 23 formed to protrude outward from the outer circumference of the hub 21. The impeller 20 may be formed of a high-strength synthetic resin material, but is not limited thereto and may be made of a metal.

Since the impeller 20 is coupled to the shaft 10 and can rotate together, the plurality of blades 23 can also rotate around the shaft 10. Air may be introduced into the air inlet 71 by the rotation of the plurality of blades 23.

For example, air provided outside the fan motor 1 may be introduced into the fan motor 1 through the air inlet 71 by the rotation of the plurality of blades 23, and through this process, the fan motor 1 ) Can generate suction power in a vacuum cleaner equipped.

The rolling bearing 30 may rotatably support the shaft 10. The rolling bearing 30 may be provided in the rolling bearing bracket 31, and may include an inner ring, a rolling member, and an outer ring.

The rolling bearing 30 is shown to support one side that is the upper portion of the shaft 10 in FIG. 1, but is not limited thereto, and may support the other side of the shaft 10 so as to be rotatable. That is, the rolling bearing 30 may support the lower portion of the shaft 10.

The rotor 40 may include end caps 41 and 45 and a magnet 43. The end caps 41 and 45 may be provided at upper and lower portions of the magnet 43, respectively, and may serve to fix the magnet 43.

The magnet 43 can be rotated by the stator 50 to be described later, and is coupled to the shaft 10. As a result, rotation of the magnet 43 may cause rotation of the shaft 10. However, the present invention is not limited thereto, and the magnet 43 may not be provided in contact with the shaft 10 and may be coupled to the shaft 10 through a separate member. For example, the magnet 43 may be provided in the rotor core (not shown), and the rotor core (not shown) may be coupled to the shaft 10 to transmit power to the shaft 10.

The magnet 43 may be provided with a magnetic material, may be an electromagnet that forms a magnetic field only when a current flows, or may be a permanent magnet that forms a magnetic field without being supplied with current from the outside. When the magnet 43 is a permanent magnet, the magnet 43 may be a rare earth magnet, an Arnico magnet, or a ferrite magnet.

The stator 50 may include a stator core 51, an insulator 53, and a coil 55.

The stator core 51 may be provided outside the rotor 40. That is, along the circumference of the outer circumferential surface of the rotor 40, the outer circumferential surface and the predetermined distance may be provided.

The stator core 51 may form a magnetic path by the rotor 40 and may form the appearance of the stator 50. In addition, the insulator 53 may be coupled to the stator core 51. The coil 55 may be provided in the insulator 53 coupled to the stator core 51. Accordingly, even when current is applied to the coil 55, insulation between the coil 55 and the stator core 51 may be achieved by the insulator 53.

Eventually, a current is applied to the coil 55 so that the magnet 43 rotates, and the shaft 10 coupled with the magnet 43 rotates to transmit power.

The air bearing 60 may include a bush 61 and an air bearing bracket 63.

The bush 61 may be provided with the shaft 10 in the center and spaced apart from the outer peripheral surface by a predetermined distance along the outer peripheral surface of the shaft 10. In addition, the bush 61 may be provided with a plurality of coupling grooves 65, and the coupling groove 65 may be provided in a groove shape from the inner peripheral surface of the bush 61 toward the outer peripheral surface.

A fixing member 69 may be provided on the lower surface of the bush 61. The fixing member 69 may prevent the air bearing 60 including the bush from moving downward in the axial direction. In addition, the fixing member 69 may be provided with a stepped in a shape corresponding to the lower surface of the bush (61). On the other hand, the corresponding here may include a flat portion such as the shape of the bottom surface of the bush 61, and a shape that can contact a portion of the bottom surface of the bush 61 so that the bush 61 cannot move downward in the axial direction. Means.

The air bearing bracket 63 forms the exterior of the air bearing 60, and the air bearing 60 may be provided therein. The above-described fixing member 69 may be provided in contact with the lower surface of the air bearing bracket 63.

The inner circumferential surface of the air bearing bracket 63 may be provided at a predetermined distance from the bush 61. Therefore, when the elastic member 67 is coupled to the coupling groove 65 provided in the bush 61, the elastic member 67 may be provided in contact with the inner circumferential surface of the bush 61 and the air bearing bracket 63.

Further, the air bearing bracket 63 may have a stepped upper surface thereof. The stepped jaws may be provided to protrude toward the shaft 10 from the upper surface of the air bearing bracket 63. That is, as the stepped jaws are provided in the air bearing bracket 63, it is possible to prevent the air bearing 60 from moving upward in the axial direction.

However, the present invention is not limited thereto, and the air bearing 60 may also be provided on one side of the shaft 10 to rotatably support the shaft 10 like the rolling bearing 30 described above. That is, when the air bearing 60 is provided on the upper part of the shaft 10 to rotatably support the shaft 10, the rolling bearing 30 is provided at the lower part of the shaft 10 to rotate the shaft 10. I can support it as much as possible.

However, as shown in FIG. 1, when the inner diameter of the rolling bearing 30 is smaller than the inner diameter of the air bearing 60, the air bearing 60 from the other side (lower) of the shaft 10 It may be desirable to support (10) rotatably.

As a result, the rotor 40 may rotate by interaction with the stator 50. In addition, since the rotor 40 is coupled to the shaft 10, the rotation of the rotor 40 may cause the shaft 10 to rotate. Rotation of the shaft 10 can induce rotation of the impeller 20 coupled with the shaft 10, and the rotation of the impeller 20 allows air provided outside the fan motor 1 to flow through the air inlet 71. It can flow through.

The flow of air introduced from the outside through the air inlet 71 forms an air flow, and according to the formation of the air flow, the product incorporating the fan motor 1 may generate suction power.

Meanwhile, air introduced through the air inlet 71 may be discharged through the discharge port 73. In addition, RPM (Revolution per minute) of the impeller 20 may be sufficiently high to generate heat, which may eventually cause overheating of the rotor 40 and stator 50.

Accordingly, external air is introduced through the cooling air inlet 75 provided on the lower surface of the motor housing 80, and the external air introduced through the cooling air inlet 75 includes the rotor 40 and the stator 50. The composition can be cooled and discharged through the discharge port 73.

The reason that external air can be introduced through the cooling air inlet 75 is because the air provided around the impeller 20 according to Bernoulli's principle has a higher speed according to the rotation of the impeller 20 and thus has less pressure. to be.

Accordingly, the fan motor 1 may be driven as described above, and the above-described configurations surround the lower portion of the impeller housing 90 and the shaft 10 surrounding the upper portion of the shaft 10, and the rotor 40 and the stator ( It may be provided in the motor housing 80 provided to surround 50). In addition, the impeller housing 90 and the motor housing 80 may be provided integrally.

3 is an exploded perspective view of an embodiment of the fan motor 1.

Referring to FIG. 3, an air bearing bracket 63 may be provided on a lower surface of the motor housing 80. Specifically, the air bearing bracket 63 may be provided at a predetermined distance along the outer periphery of the lower surface of the motor housing, and a cooling air inlet 75 may be provided between spaces spaced at a predetermined distance. In other words, in order to form the cooling air inlet 75, a plurality of ribs radiating from the outer circumferential surface of the air bearing bracket 63 are connected to the periphery of the lower surface of the motor housing 80 with the air bearing bracket 63 as the center. It can be provided.

The air bearing bracket 63 may have an outer circumferential surface and an inner circumferential surface since there is a space for accommodating the air bearing 60 therein. Accordingly, the bush 61 to which the elastic member 67 is coupled is introduced into the air bearing bracket 63, and the fixing member 69 corresponding to the lower surface shape of the air bearing bracket 63 is formed of the air bearing bracket 63. It is coupled to the lower surface can prevent the axial movement of the air bearing (60).

However, the shape of the air bearing 60 is not limited thereto, and the shaft 10 may be rotatably supported in other shapes.

4 is a view showing another embodiment of the air bearing 60.

Except for the same configuration as the previous configuration, and referring to FIG. 4, the air bearing 60 rotates the shaft 10 without a separate fixing member 69 provided on the lower surface of the air bearing bracket 63 I can support it as much as possible.

A snap ring coupling groove 64 to which the snap ring 68 is coupled may be provided at a lower portion of the air bearing bracket 63. That is, the snap ring coupling groove 64 provided under the bush 61 may be provided by forming a groove from the inner peripheral surface of the air bearing bracket 63 toward the outer peripheral surface.

More specifically, refer to FIG. 5 to describe the form in which the snap ring 68 is coupled. 5(a) is a view showing a state in which the snap ring 68 is not subjected to pressure, and FIG. 5(b) is a view showing a state in which an external force acts on the snap ring 68.

The snap ring 68 may be made of an elastic material and may have a restoring force. Here, if there is a restoring force, if an external force is applied to the snap ring 68 from the outside, the shape of the snap ring 68 may be deformed while the external force is applied, but when the external force disappears, the snap ring 68 returns to the state before the external force was applied. It means to be able to go.

In other words, the snap ring 68 may have D1 as a radius before external force is applied, and may have D2 as a radius when external force is applied. D1 may be a value exceeding D2.

Referring again to Figs. 4 and 6, the coupling process of the snap ring 68 will be described. Fig. 6 is a fan having a configuration in which the snap ring 68 is combined instead of the fixing member to prevent the axial movement of the air bearing 60 It is an assembled perspective view of the motor 1.

A hole through which the snap ring 68 can flow may be provided under the air bearing bracket 63. The hole may be provided under the snap ring coupling groove 64. In addition, the radius H of the hole may be smaller than the radius D1 before the snap ring 68 receives an external force, and may be larger than the radius D2 after the snap ring 68 receives the external force.

Accordingly, the bush 61 to which the elastic member 67 is coupled into the air bearing bracket 63 is introduced through the hole and is in close contact with the upper inner circumferential surface of the air bearing bracket 63 to be fixed, and then the snap ring 68 may be coupled. .

More specifically, when an external force is applied to the snap ring 68 to form a radius (D2) to pass through the hole, and the radius (D1) is formed by removing the external force, the snap ring 68 is seated and provided in the snap ring coupling groove 64. Can be.

Accordingly, the shaft 10 may be rotatably supported by the rolling bearing 30 and the air bearing 60 described above. In addition, as described above, when the shaft 10 rotates at high speed, the elastic member 67 may be coupled to the air bearing 60 to reduce vibration and heat generation. In addition, as described above, the elastic member 67 may be in contact with the inner circumferential surface of the air bearing bracket 63 and the bush 61 at the same time to support the shaft 10 rotatably, which is the rolling bearing 30 and the air bearing ( 60) can have an easier effect to match the alignment.

However, when two or more rolling bearings are provided in the rolling bearing bracket, alignment between the rolling bearings may be problematic. That is, although the resonant frequency of the rolling bearing is quite high, vibration and noise may occur in the rolling bearing when the rotating shaft is rotated at ultra high speed while miniaturizing and lightening the fan motor. Accordingly, vibration and noise can be reduced by applying a preload to the ball bearing, and it can be seen that a specific preload method is important.

7 is a view showing a cross section of a structure for preloading a bearing using an elastic member.

Referring to FIG. 7, the bearing assembly 100 may include a shaft 101, a first bearing 110, an elastic member 120, a second bearing 130, and a bracket 140. .

The first bearing 110 may include an inner ring, a rolling member, and an outer ring. The inner ring of the first bearing 110 may be press-fitted to the first support part 113 of the shaft 110. In addition, the elastic member 120 may be provided in contact with the outer ring of the first bearing 110.

The second bearing 130 may include an inner ring, a rolling member, and an outer ring. The inner ring of the second bearing 110 may be press-fitted to the second support part 133 of the shaft 110. In addition, the elastic member 120 may be provided in contact with the outer ring of the second bearing 130.

The elastic member 130 may have an elastic force and may have a spring shape. That is, when the elastic member 130 is provided between the first bearing 110 and the second bearing 130 in a compressed state, the tensile force in the direction of separating the first bearing 110 and the second bearing 130 from each other (tention) can act.

As a result, when the elastic member 120 is provided so as to be in contact with the lower surface of the outer ring of the first bearing 110 and the upper surface of the outer ring of the second bearing 130, the elastic member 120 includes the first bearing 110 and the second bearing ( A tensile force (F) can be applied to separate 130) from each other. Therefore, the inner ring of the first bearing 110 and the inner ring of the second bearing 130 that are press-fitted and fixed are fixed to the shaft 101, but the outer ring of the first bearing 110 and the outer ring of the second bearing 130 Silver may be provided spaced apart from each other compared to before the tensile force (F) is applied.

When the outer ring of the first bearing 110 and the outer ring of the second bearing 130 are provided to be spaced apart from each other, the outer ring of the first bearing 110 is bonded and fixed to the third support part 111 in contact with the inner circumferential surface of the bracket 140 Can be. In addition, the outer ring of the second bearing 130 may be bonded and fixed to the fourth support part 131 in contact with the inner circumferential surface of the bracket 140.

Accordingly, preloading of the first bearing 110 and the second bearing 130 included in the bearing assembly 100 may be performed. In this case, since the bonding process must be performed after receiving the tensile force due to the elastic member 120, the process may be complicated. That is, after the elastic member 120 is provided between the first bearing 110 and the second bearing 130 in a compressed state, the order may be problematic because bonding must be performed.

In addition, in the case of bonding, since the bonding site where bonding is performed can absorb the pressure applied between the outer ring of the first bearing 110 and the outer ring of the second bearing 130, a problem that less preload is applied may occur. .

8 is a view showing a cross section of a preload structure of a bearing using another elastic member.

8, the bearing assembly 200 includes a shaft 201, a first bearing 210 and. It may include an elastic member 220, a second bearing 230, and a bracket 241.

Except for overlapping content with FIG. 7, the elastic member 220 may be a wave washer. The wave washer is basically provided in a ring shape, and the height can be changed along the circumference. That is, the wave washer may have a plurality of peaks and valleys. In the case of a wave washer, when a force is applied from the outside, it can generate a tensile force.

The inner ring of the first bearing 210 may be press-fitted to the first support part 213 in contact with the shaft 201. The inner ring of the second bearing 230 may be press-fitted to the second support portion 233 in contact with the shaft 201.

The bracket 240 may be provided on an upper end and may have a stepped portion 241 protruding toward the shaft 201. The elastic member 220 may be provided in contact with the lower surface of the stepped portion 241 and the upper surface of the outer ring of the first bearing 210.

When the elastic member 220 receives an external force to generate a tensile force, the outer ring of the first bearing 210 may be provided to be spaced apart lower than before the tensile force is generated. However, in this case, the outer ring of the second bearing 230 is fixed to the lower end of the bracket 240, and the reaction force by the tensile force applied to the outer ring of the first bearing 210 causes the outer ring of the second bearing 230 to become the inner ring. It can be provided higher.

As a result, the load support direction D'by the tensile force F'may be determined in a form radiating based on the inner ring of the first bearing 210 and the inner ring of the second bearing 230. In this case, the load bearing direction D'is an unfavorable load bearing direction D'as the inner ring of the first bearing 210 and the inner ring of the second bearing 230 support the shaft 201 more narrowly. have. In addition, since the bonding process must be performed after the tensile force is applied by the elastic member 220, it may be more complicated.

Accordingly, the present invention may provide a bearing assembly capable of adjusting the preload degree, which is easier in the process of assembling the bearing assembly because there is no or less bonding process.

9 is a view showing a bearing assembly according to an embodiment of the present invention.

Referring to FIG. 9, the bearing assembly 300 may include a shaft 301, a first bearing 310, a second bearing 330, and a bracket 340.

The shaft 301 may include a central portion 303. The central portion 303 may be provided to extend from the shaft 301 toward the bracket 340 at a predetermined interval. That is, the central portion 303 may be part of a cylindrical shape.

In addition, the shaft 301 may include a screw thread 305 formed in a predetermined area above the central portion 303. That is, a part of the outer circumferential surface of the shaft 301 may be provided with a thread 305.

The first bearing 310 may include an inner ring 319, a rolling member 317, and an outer ring 315. The inner ring 319 forms an inner side of the first bearing 310 and may be provided in contact with the shaft 301. The outer ring 315 is provided in contact with the bracket inner circumferential surface 340i, and may be provided by being press-fitted to the press-fit portion 313. The press-fit portion 313 constitutes a part of the bracket inner peripheral surface 340i and may be a portion in contact with the outer ring 315. Alternatively, the press-fit portion 313 is a separate component constituting a part of the bracket inner peripheral surface 340i, and may refer to a groove provided from the inner peripheral surface 340i toward the outer peripheral surface 340o.

The rolling member 317 is provided between the inner ring 319 and the outer ring 315 and may be provided in contact with the inner ring 319 and the outer ring 315. The rolling member 317 may have a ball shape. Therefore, when the inner ring 319 rotates according to the rotation of the shaft 301, the rolling member 317 may perform a rolling motion or a sliding motion between the outer ring 315 and the inner ring 319 fixed so as not to rotate. .

The second bearing 330 may include an inner ring 339, a rolling member 337 and an outer ring 315. The inner ring 339 may be provided by being press-fitted to the press-fit portion 333 of the shaft 301. The outer ring 335 may be provided by being press-fitted to the press-fit portion 333 of the inner circumferential surface of the bracket 340. The rolling member 337 may perform a rolling motion or a sliding motion between the inner ring 339 and the outer ring 335.

The bracket 340 is provided on the upper surface, and may include a stepped portion protruding from the inner peripheral surface of the bracket 340 toward the shaft 301.

The fixing member 350 may be coupled to the shaft 301 and may be movable in the axial direction. Also, after moving in the axial direction, it may be fixed in a state coupled to the shaft 301.

Now, an example of the preload sequence of the bearing assembly 300 will be described, the outer ring 315 of the first bearing 310 can be press-fitted to the press-fit portion 313, and the inner ring 339 of the second bearing 330 ) Can be fixed to the press-fit portion 333 of the shaft 301. That is, one bearing may be press-fitted into the bracket 340 and the other bearing may be press-fitted into the shaft 301. Meanwhile, the outer ring 315 of the first bearing 310 may be fixed in contact with a stepped portion provided on the upper end of the bracket 340. In addition, the inner ring 339 of the second bearing 330 may be fixed in contact with the central lower surface 303B.

Thereafter, the shaft 301 to which the second bearing 330 is fixed may be provided by sliding between the inner rings 319 of the first bearing 310. That is, the shaft 301 to which the second bearing 330 is fixed may be provided through the bracket 340.

Thereafter, the outer ring 335 of the second bearing 330 may be press-fitted to the press-fit portion 333 of the bracket inner peripheral surface 340i.

Thereafter, the fixing member 350 may pressurize the inner ring 319 of the first bearing 310. The pressurized inner ring 319 may be pressed so as to contact the upper central surface 303T. Meanwhile, the fixing member 350 may be a nut corresponding to the screw thread 305. However, the present invention is not limited thereto, and a member capable of moving and fixing along the axial direction will be considered to be included in the fixing member 350.

In addition, when the fixing member 350 is a nut, the degree of movement in the axial direction along the screw thread 305 can be adjusted. That is, the degree of preload may be adjustable.

Accordingly, the inner ring 319 of the first bearing 310 may be provided below the outer ring 315 in the axial direction. The inner ring 339 of the second bearing 330 may be provided above the outer ring 335 in the axial direction.

Accordingly, the rolling member 317 of the first bearing 310 may be provided in contact with the upper portion of the inner ring 319 and the lower portion of the outer ring 315. The rolling member 337 of the second bearing 330 may be provided in contact with a lower portion of the inner ring 339 and an upper portion of the outer ring 335.

That is, portions of the rolling member 317 in contact with the inner ring 319 and the outer ring 315 may be different from each other. A portion of the rolling member 317 in contact with the inner ring 319 may be formed higher than a portion in contact with the outer ring 315.

A portion of the rolling member 337 in contact with the inner ring 339 may be formed lower than a portion in contact with the outer ring 335.

Accordingly, a section in which the shaft 301 is supported through the first bearing 310 and the second bearing 330 may be lengthened. That is, the rotation of the shaft 301 may be supported from a portion in which the inner ring 319 contacts the rolling member 317 to a portion in which the inner ring 339 contacts the rolling member 337.

Accordingly, according to a preferred embodiment of the present invention, it is possible to adjust the degree of preload of the bearing, and to have an advantageous load support direction (D").

10 is a view showing a bearing assembly according to another embodiment of the present invention.

Except for redundant explanation, the bearing assembly 400 may include a plurality of fastening holes 405 and a fixing member 450.

The plurality of fastening holes 405 may be located above the central portion 403 and may be formed to be inclined downward. The plurality of fastening holes 405 may be formed at equal intervals. In addition, each fastening hole 405 may have a thread 407.

The fixing member 450 may be a bolt. When the fixing member 450 is a bolt, a thread corresponding to the thread 407 may be provided. More specifically, the bolt may include a body portion provided with a thread and a cap provided over the body portion.

Accordingly, the fixing member 450 may be gradually inserted and fixed in the fastening hole 405. By controlling the degree to which the fixing member 450 flows into the fastening hole 405, the preload degree of the bearing assembly can be adjusted.

Even in this case, the inner ring 419 of the first bearing 410 may be positioned lower than the outer ring 415. In addition, the inner ring 435 of the second bearing 430 may be positioned higher than the outer ring 439. In the end, it can have a more advantageous load bearing direction (D''').

The present invention is not limited to the above-described embodiments, and as can be seen from the appended claims, modifications can be made by those of ordinary skill in the field to which the present invention belongs, and such modifications are within the scope of the present invention. .

Bearing assembly: 300 Shaft: 301
Shaft thread: 305 Center: 303
Center top: 303T Center bottom: 303B
First bearing: 310 Press-in part: 313
Outer ring: 315 Rolling member: 317
Inner ring: 319 Second bearing: 330
Press-fit part: 333 Outer ring: 335
Rolling member: 337 Inner ring: 339
Bracket: 340 Bracket inner surface: 340i
Fixed member: 350 Load bearing direction: D''
Bearing Assembly: 400 Shaft: 401
Center: 403 Fastening hole: 405
Fastening hole thread: 407 1st bearing: 410
Press-fit part: 413 Outer ring: 415
Rolling member: 417 Inner ring: 419
2nd bearing: 430 inner ring: 435
Rolling member: 437 Outer ring: 439
Bracket: 440 Inner side of bracket: 440i
Fixed member: 450 Load bearing direction: D'''

Claims (10)

A shaft forming a rotating shaft;
A center protruding from the shaft in a radial direction of the rotation shaft;
A first bearing provided on the upper portion of the center and including an outer ring and an inner ring;
A second bearing provided in contact with a lower surface of the center and including an outer ring and an inner ring;
A bracket in which the outer ring of the first bearing and the outer ring of the second bearing are press-fitted to the inner circumferential surface, and the shaft is provided through it; And
Includes; a fixing member provided on the upper portion of the first bearing, coupled to the shaft and movable along the axial direction,
The inner ring of the first bearing is provided so that the shaft is slidable between the inner rings of the first bearing, and the inner ring of the second bearing is provided to be press-fitted to the shaft,
As the fixing member is moved toward the center, the fixing member applies a load to the inner ring of the first bearing, and the inner ring of the first bearing is pressed so as to contact the upper surface of the center, thereby preloading the bearing. Bearing assembly characterized by. The method of claim 1,
The first bearing further comprises a rolling member provided between the outer ring and the inner ring,
The second bearing further comprises a rolling member provided between the outer ring and the inner ring. The method of claim 2,
The bracket includes a stepped portion extending toward the shaft at an upper end,
The outer ring of the first bearing is press-fitted to an upper end of the inner circumferential surface of the bracket, so that the lower surface of the stepped portion and the upper surface of the first bearing are in contact with each other. The method of claim 3,
The shaft is provided with a thread on the upper portion of the center,
The fixing member is a bearing assembly, characterized in that the inner circumferential surface is a nut having a fastening portion corresponding to the thread. The method of claim 3,
The shaft,
It is provided on the upper portion of the center, and includes a plurality of fastening holes formed at equal intervals along the outer peripheral surface of the shaft,
Each of the plurality of fastening holes is provided to be inclined downward,
The fixing member is a bearing assembly, characterized in that the bolt corresponding to the fastening hole. A shaft forming a rotating shaft;
A central portion protruding from the shaft in a radial direction of the rotation shaft;
An impeller rotatably coupled to the shaft;
A first bearing located under the impeller and supporting the rotation of the shaft, provided at an upper portion of the center and including an outer ring and an inner ring; and a second bearing provided in contact with the lower surface of the center and including an outer ring and an inner ring A rolling bearing comprising;
A bracket in which the outer ring of the first bearing and the outer ring of the second bearing are press-fitted to the inner circumferential surface, and the shaft is provided through it;
A fixing member provided on the upper portion of the first bearing and coupled to the shaft to move along an axial direction;
A rotor positioned under the rolling bearing and rotatably coupled to the shaft;
A stator surrounding the outside of the rotor; And
Includes; an air bearing positioned below the rotor and the stator and supporting the rotation of the shaft,
The inner ring of the first bearing is provided so that the shaft is slidable between the inner rings of the first bearing, and the inner ring of the second bearing is provided to be press-fitted to the shaft,
As the fixing member is moved toward the center, the fixing member applies a load to the inner ring of the first bearing, and the inner ring of the first bearing is pressed so as to contact the upper surface of the center, thereby preloading the rolling bearing. Fan motor, characterized in that the. The method of claim 6,
The bracket includes a stepped portion extending toward the shaft at an upper end,
The outer ring of the first bearing is press-fitted to an upper end of the inner circumferential surface of the bracket, and the lower surface of the stepped portion and the upper surface of the first bearing are in contact with each other. The method of claim 7,
The shaft is provided with a thread on the upper portion of the center,
The fixing member is a fan motor, characterized in that the inner circumferential surface is a nut having a fastening portion corresponding to the screw thread. The method of claim 7,
The shaft,
It is provided on the upper portion of the center, and includes a plurality of fastening holes formed at equal intervals along the outer peripheral surface of the shaft,
Each of the plurality of fastening holes is provided to be inclined downward,
The fixing member is a fan motor, characterized in that the bolt corresponding to the fastening hole. A shaft forming a rotating shaft; A central portion protruding from the shaft in a radial direction of the rotation shaft; A first bearing including an outer ring and an inner ring; A second bearing including an outer ring and an inner ring; A bracket through which the shaft is provided and includes a stepped portion extending toward the shaft at an upper end; And a fixing member movable along an axial direction,
Press-fitting and fixing the outer ring of the first bearing in contact with the inner circumferential surface of the bracket and the lower surface of the stepped portion, and press-fitting the inner ring of the second bearing to the shaft in contact with the lower surface of the central portion;
Sliding the shaft through the inner rings of the first bearing;
Coupling the fixing member with the shaft so as to be positioned above the first bearing;
Including; moving the fixing member downward in the axial direction,
As the fixing member is moved toward the center, the fixing member applies a load to the inner ring of the first bearing, and the inner ring of the first bearing is pressed to contact the upper surface of the center to preload the bearing. Preloading method for bearing assembly

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