KR20200125536A - Motor assembly and manufacturing method thereof - Google Patents

Abstract

Disclosed is a motor assembly with high reliability and durability. According to an embodiment of the present invention, the motor assembly comprises: a rotating shaft; a rotor installed on the rotating shaft; a stator surrounding an outer side of the rotor to be spaced apart from the rotor by a predetermined distance along a radial direction of the rotating shaft; an impeller installed on the rotating shaft to be spaced apart from the rotor by a predetermined distance along an axial direction of the rotating shaft; a bearing housing provided with a through hole through which the rotating shaft passes and installed between the rotor and the impeller; and a rolling bearing installed on the bearing housing and supporting the rotating shaft. The rotating shaft has a protrusion unit which is formed in a part overlapping with the bearing housing based on the radial direction of the rotating shaft and protrudes in a direction toward the bearing housing. A predetermined gap in which high-pressure gas can flow is formed between an inner circumferential surface of the bearing housing and an outer circumferential surface of the protrusion unit during rotation of the rotating shaft, and the rotating shaft is supported in the radial direction of the rotating shaft by the high-pressure gas flowing in the gap.

Description

Motor assembly and its manufacturing method {MOTOR ASSEMBLY AND MANUFACTURING METHOD THEREOF}

Embodiments of the present invention relate to a motor assembly and a manufacturing method thereof, and more particularly, to a motor assembly including a bearing supporting a rotating shaft and a manufacturing method thereof.

The motor may be installed in a home appliance such as a vacuum cleaner or a hair dryer, and may function as a driving source generating rotational force. The motor may be coupled to a fan, and in this case, the rotational force of the motor may be transmitted to the fan, so that airflow may be generated according to the rotation of the fan.

Since the vacuum cleaners and hair dryers for example above are operated by the user's own hand, it is the key of recent engineering to manufacture as much lighter weight and smaller volume as possible, provided that the necessary functions are improved or at least kept the same. There is no need to increase the value.

In general, in designing and manufacturing home appliances, as well as vacuum cleaners and hair dryers, it is required to improve or at least maintain unique functions while reducing weight and miniaturization. This is to maximize the user's convenience, and it is a matter that must be considered indispensable to secure differentiation from competing products in the fierce market.

As an example, in the case of a cleaner, it is required to reduce the size and weight of the motor while improving the output of the motor. For this, high-speed rotation of the motor is essential. However, the high-speed rotation of the motor inevitably causes noise and vibration problems.

In order to cope with these noise and vibration problems and to secure the reliability and durability of a cleaner, it is necessary to design a bearing capable of supporting the rotating shaft of a motor rotating at high speed for as long as possible without deformation or damage.

Embodiments of the present invention solve the provision of a motor assembly having high reliability and durability in supporting a rotating shaft of a motor rotating at high speed and a method of manufacturing the same while satisfying the requirements for miniaturization and weight reduction of a motor assembly installed in a home appliance. Make it the task you want to do.

In addition, it is an object to be solved to provide a motor assembly and a method of manufacturing the same in which alignment between a plurality of bearings is easy while supporting a rotating shaft on one side.

An embodiment of the present invention relates to a motor assembly in which a rolling bearing and a gas bearing are installed to be spaced apart from each other along an axial direction of a rotation shaft in one bearing housing, and a manufacturing method thereof.

An embodiment of the present invention includes a rotating shaft, a rotor installed on the rotating shaft, a stator surrounding the outer side of the rotor so as to be spaced apart from the rotor by a predetermined distance along the radial direction of the rotating shaft, and a predetermined distance from the rotor along the axial direction of the rotating shaft. An impeller installed on the rotation shaft, and a through hole through which the rotation shaft passes, and a bearing housing installed between the rotor and the impeller, and a rolling bearing installed in the bearing housing to support the rotation shaft, and the rotation shaft indicates a radial direction of the rotation shaft. It is formed in a part overlapping with the bearing housing as a reference, and has a protrusion protruding in a direction toward the bearing housing, and a predetermined gap through which high-pressure gas can flow between the inner circumferential surface of the bearing housing and the outer circumferential surface of the protrusion when the rotation shaft is rotated. And the rotation shaft is supported in the radial direction of the rotation shaft by a high-pressure gas flowing in the gap.

In this embodiment, the impeller, the rolling bearing, and the protrusion may be arranged in order along the axial direction of the rotating shaft.

In this embodiment, it may further include a first coating layer formed on the inner peripheral surface of the bearing housing.

In this embodiment, the first coating layer is polytetrafluoroethylene, diamond like carbon, lubrite, molybdenum disulphide, D10, boron nitride, It may contain one or more of ceramic powder, soap, copper, lead, and soft metal.

In this embodiment, a part of the inner circumferential surface of the first coating layer is in contact with the outer circumferential surface of the rolling bearing, and a predetermined gap through which high-pressure gas can flow is formed between the other part of the inner circumferential surface of the first coating layer and the outer circumferential surface of the protrusion when the rotating shaft rotates. It is formed, and the rotating shaft may be characterized in that it is supported in the radial direction of the rotating shaft by a high-pressure gas flowing in the gap.

In this embodiment, the first coating layer is formed on a part of the inner circumferential surface of the bearing housing so as to surround the protrusion along the radial direction of the rotation shaft, and another part of the inner circumferential surface of the bearing housing contacts the outer circumferential surface of the rolling bearing, and when the rotation shaft rotates. A predetermined gap through which high-pressure gas can flow is formed between the inner circumferential surface of the first coating layer and the outer circumferential surface of the protrusion, and the rotating shaft is supported in a radial direction of the rotating shaft by the high-pressure gas flowing through the gap.

In the present embodiment, the rotation shaft may include an impeller coupling portion on which an impeller is installed, a support portion facing the bearing housing along a radial direction of the rotation shaft, and a rotor coupling portion on which the rotor is installed.

In this embodiment, the support portion has a contact portion in contact with the inner circumferential surface of the rolling bearing, and extends in the axial direction of the rotation shaft from the contact portion, and between the inner circumferential surface of the bearing housing and the outer circumferential surface of the protrusion with respect to the inner circumferential surface of the bearing housing based on the radial direction of the rotation axis It may include a connection portion spaced apart from each other with a space wider than the gap formed in the.

In this embodiment, the bearing housing surrounds the outer circumferential surface of the rolling bearing, and extends in the axial direction of the rotation shaft from the rolling bearing housing portion and a rolling bearing housing portion disposed relatively adjacent to the impeller, and surrounds the outer peripheral surface of the connection portion. , A housing connection part spaced apart from each other with a space between the connection part, and the housing connection part extending in the axial direction of the rotation axis from the housing connection part, surrounding the outer circumferential surface of the protrusion part, and arranged to be spaced apart from each other with a gap from the protrusion part, and disposed relatively adjacent to the rotor. It may include a gas bearing housing.

In the present embodiment, the rolling bearing may include an inner ring press-fitted to the outer peripheral surface of the rotating shaft, an outer ring press-fitted to the inner peripheral surface of the bearing housing, and a ball interposed between the inner ring and the outer ring.

In this embodiment, when the rotating shaft rotates, the inner ring of the rolling bearing rotates together with the rotating shaft, and the outer ring of the rolling bearing may be maintained in a fixed state by the bearing housing.

In this embodiment, the bearing housing includes a bearing fixing part protruding inwardly along the radial direction of the rotation shaft, the through hole is an empty space surrounded by the bearing fixing part, and the bearing fixing part is a rolling bearing along the axial direction of the rotation shaft. It is possible to prevent the outer ring from moving toward the impeller side.

In the present embodiment, the bearing housing includes at least one of aluminum and brass, bronze, and nickel-chromium alloy, and the nickel-chromium alloy may be characterized in that the content of nickel is greater than the content of chromium.

In this embodiment, it further includes a bush installed on the inner circumferential surface of the bearing housing, and the bush includes at least one of aluminum and brass, bronze, and nickel-chromium alloy, but between the inner circumferential surface of the bush and the outer circumferential surface of the protrusion when the rotating shaft is rotated. A gap through which high-pressure gas can flow is formed, and the rotating shaft is supported in a radial direction of the rotating shaft by the high-pressure gas flowing through the gap.

In this embodiment, it may further include a second coating layer formed on the inner peripheral surface of the bush.

In this embodiment, the second coating layer is polytetrafluoroethylene, diamond like carbon, lubrite, molybdenum disulphide, D10, boron nitride, It may contain one or more of ceramic powder, soap, copper, lead, and soft metal.

In this embodiment, a part of the inner circumferential surface of the second coating layer is in contact with the outer circumferential surface of the rolling bearing, and a predetermined gap through which high-pressure gas can flow is formed between the other part of the inner circumferential surface of the second coating layer and the outer circumferential surface of the protrusion when the rotating shaft rotates. It is formed, and the rotating shaft may be characterized in that it is supported in the radial direction of the rotating shaft by a high-pressure gas flowing in the gap.

In this embodiment, the second coating layer is formed on a part of the inner circumferential surface of the bush to surround the protrusion along the radial direction of the rotation shaft, and another part of the inner circumferential surface of the bush is in contact with the outer circumferential surface of the rolling bearing. A predetermined gap through which high-pressure gas flows is formed between the inner circumferential surface of the coating layer and the outer circumferential surface of the protrusion, and the rotating shaft is supported in a radial direction of the rotating shaft by the high-pressure gas flowing through the gap.

Another embodiment of the present invention includes the steps of press-fitting and fixing the inner ring of the rolling bearing on the outer circumferential surface of the rotating shaft, forming a coating layer by coating the inner circumferential surface of the bearing housing accommodating the rolling bearing, and installing the rotating shaft and the rolling bearing on the bearing housing. Including the step of coupling the rotating shaft and the rolling bearing to the bearing housing, the outer ring of the rolling bearing is press-fitted to the inner circumferential surface of the bearing housing or the inner circumferential surface of the coating layer, and the outer circumferential surface of the protrusion of the rotating shaft protruding along the radial direction of the rotating shaft. And an inner circumferential surface of the bearing housing, or between an outer circumferential surface of a protrusion and an inner circumferential surface of the coating layer, a method of manufacturing a motor assembly, characterized in that a predetermined space is formed in which a high-pressure gas can be accommodated when a rotating shaft is rotated.

Another embodiment of the present invention includes the steps of press-fitting the inner ring of the rolling bearing to the outer circumferential surface of the rotating shaft, forming a coating layer by coating the inner circumferential surface of the bush accommodating the rolling bearing, and installing the bush on the inner circumferential surface of the bearing housing. The step of installing the rotating shaft and the rolling bearing to the bearing housing, and installing the rotating shaft and the rolling bearing to the bearing housing includes press-fitting and fixing the outer ring of the rolling bearing to the inner circumferential surface of the bush or the inner circumferential surface of the coating layer, and A motor assembly, characterized in that a predetermined space is formed in which high-pressure gas can be accommodated when the rotating shaft is rotated between the outer circumferential surface of the protrusion of the rotating shaft and the inner circumferential surface of the bush, or between the outer circumferential surface of the protrusion and the inner circumferential surface of the coating layer protruding along the radial direction. The manufacturing method is disclosed.

According to the motor assembly and its manufacturing method according to the embodiments of the present invention as described above, the rolling bearing and the gas bearing accommodated in one bearing housing together support the rotating shaft on one side, making it easier to support the rotating shaft on both sides. It is possible to reduce the rotation center error between them.

In addition, it is possible to reduce the size and load of the motor assembly by configuring the bearing housing for accommodating the rolling bearing and the gas bearing into one, thereby making the motor assembly compact and lightweight.

In addition, by minimizing the rotational center error between a plurality of bearings installed on the rotational shaft, vibration and noise generated when the motor is rotated at high speed can be alleviated to stably support the rotational shaft.

In addition, since the rotating shaft can be stably supported without using consumables such as O-rings, which need to be replaced due to wear, not only can the durability of the motor assembly be improved, but also the lifespan can be extended.

Of course, the scope of the embodiments of the present invention is not limited by these effects.

Embodiments of the present invention can be easily understood by the following detailed description and a combination of the accompanying drawings, and reference numerals denote structural elements.
1 is a cross-sectional view showing each configuration of a motor assembly according to an embodiment of the present invention.
FIG. 2 is an exploded perspective view showing the motor assembly shown in FIG. 1 by exploding.
FIG. 3 is a cross-sectional view illustrating a part of the motor assembly shown in FIG. 1 by separating it.
FIG. 4(a) is a cross-sectional view showing a state viewed from above by cutting line I-I' of FIG. 3.
FIG. 4(b) is a cross-sectional view showing a state viewed from above by cutting line II-II' of FIG. 3.
5 is a cross-sectional view showing a modified example of the motor assembly shown in FIG. 3.
FIG. 6(a) is a cross-sectional view showing a state viewed from above by cutting line III-III' of FIG. 5.
FIG. 6(b) is a cross-sectional view showing a state viewed from above by cutting line IV-IV' of FIG. 5.
7 is a cross-sectional view showing another modified example of the motor assembly shown in FIG. 3.
FIG. 8(a) is a cross-sectional view showing a state viewed from above by cutting the line V-V' of FIG. 7.
FIG. 8(b) is a cross-sectional view illustrating a state viewed from above by cutting line VI-VI' of FIG. 7.
9 is a cross-sectional view illustrating another modified example of the motor assembly shown in FIG. 3.
FIG. 10(a) is a cross-sectional view showing a state viewed from above by cutting the line VII-VII' shown in FIG. 9.
FIG. 10(b) is a cross-sectional view showing a state viewed from above by cutting line VIII-VIII' shown in FIG. 9.
11 is a flowchart schematically showing a method of manufacturing the motor assembly shown in FIGS. 3 and 5.
12 is a flow chart schematically illustrating a method of manufacturing the motor assembly shown in FIGS. 7 and 9.

The terms used in the present specification have selected general terms that are currently widely used as possible while taking the functions of the embodiments of the present invention into consideration, but this may vary according to the intention or precedent of a person skilled in the art, the emergence of new technologies, and the like. In addition, in certain cases, there are terms arbitrarily selected by the applicant, and in this case, the meaning of the terms will be described in detail in the description of the corresponding invention. Therefore, the terms used in the present specification should be defined based on the meaning of the term and the contents throughout the specification, not a simple name of the term.

In addition, when a certain part "includes" a certain component throughout the specification, this means that other components may be further included rather than excluding other components unless otherwise stated.

In addition, regardless of the reference numerals, identical or corresponding components are given the same reference numbers, and duplicate descriptions thereof will be omitted, and the size and shape of each component member shown for convenience of explanation may be exaggerated or reduced. have.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those of ordinary skill in the art to which the embodiments of the present invention belong can easily implement. However, embodiments of the present invention may be implemented in various different forms and are not limited to the embodiments described herein.

1 is a cross-sectional view showing each configuration of a motor assembly according to an embodiment of the present invention, and FIG. 2 is an exploded perspective view illustrating the motor assembly shown in FIG.

1 and 2, the motor assembly 100 may include a rotating shaft 110, a rotor 120, a stator 130, an impeller 140, a bearing housing 150, and a rolling bearing 160. , These components may be installed inside the inlet body 51 and the motor housing 52 forming the exterior of the motor assembly 100.

First, the inlet body 51 may include an inlet 51A through which air is sucked, and may be disposed to surround the outer circumference of the impeller 140. That is, an impeller space S1 in which the impeller 140 is rotatably accommodated may be formed inside the inlet body 51, and the appearance thereof corresponds to the shape of the impeller 140, while the impeller space S1 The inner surface may be formed to be curved so as to stably guide the gas flowing along the line.

Specifically, the opposite side of the inlet 51A of the inlet body 51 may be coupled to the motor housing 52 to form the exterior of the motor assembly 100. The fastening portions of the inlet body 51 and the motor housing 52 may be fastened to be in close contact with each other so that air flowing inside the motor assembly 100 does not flow out. That is, it is preferable that the inlet body 51 and the motor housing 52 are securely fastened so that no gap is formed, and various methods such as screwing or fitting may be used as the fastening method. It is not limited to any particular method.

The motor housing 52 may be formed to surround the stator 130 and be fastened to the inlet body 51. In detail, a motor space S2 in which the rotation shaft 110, the rotor 120, and the stator 130 may be accommodated may be formed in the motor housing 52. The motor housing 52 may include an outlet 521 through which air guided from the impeller space S1 to the motor space S2 is discharged to the outside of the motor housing 52 by rotation of the impeller 140, The outlet 521 may be formed on the opposite side of the inlet 51A based on the air flow direction.

The inlet body 51 and the motor housing 52 may be a kind of hollow case, and may be disposed so that the rotation shaft 110 extends in the axial direction L in a center empty space. As shown in the drawing, the rotation shaft 110 may not be directly supported by the inlet body 51 or the motor housing 52. That is, the inlet body 51 or the motor housing 52 may not be provided with a separate rotation shaft supporter (tentative name) for supporting the rotation shaft 110.

The rotation shaft 110 may be extended to cross the impeller space S1 and the motor space S2 in the axial direction L. Specifically, one end 110A of the rotation shaft 110 may be disposed on the motor housing 52 side, and the other end 110B of the rotation shaft 110 may be disposed on the inlet body 51 side.

Each of the one end 110A of the rotation shaft 110 and the other end 110B of the rotation shaft 110 may be a free end that is not supported by the motor housing 52 and the bearing housing 150 to be described later. Here, the "free end" may mean both ends of the rotating shaft 110 that are not supported or restricted by any of the components.

Meanwhile, as will be described later, the rotation shaft 110 may have a support 113 between one end 110A and the other end 110B supported by a plurality of bearings. Here, the plurality of bearings refers to a rolling bearing 160, which will be described later, and a gas bearing implemented by a coupling structure between the protrusion 111 of the rotation shaft 110 and the bearing housing 150, and these are detailed below. It will be described as.

One end 110A of the rotation shaft 110 may be close to the rotor 120 of the rotor 120 and the impeller 140, and may be a free end of the rotor 120 side. In addition, the other end 110B of the rotation shaft 110 may be close to the impeller 140 of the rotor 120 and the impeller 140, and may be a free end on the impeller 140 side.

Specifically, the rotation shaft 110 may include a protrusion 111, an impeller coupling portion 112, a support portion 113, and a rotor coupling portion 114.

The protrusion 111 is formed on a part of the rotation shaft 110 overlapping the bearing housing 150 based on the radial direction R of the rotation shaft 110, and may protrude in a direction toward the bearing housing 150. The relationship between the protrusion 111 and the bearing housing 150, their actions and effects will be described later in detail together with the description of the bearing housing 150 below.

The impeller coupling part 112 is a part of the rotation shaft 110 in which the impeller 140 is installed, is a part adjacent to the other end 110B of the rotation shaft 110, and may be disposed in the impeller space S1.

The support part 113 is a part of the rotation shaft 110 facing the bearing housing 150 along the radial direction R of the rotation shaft 110, and between the impeller coupling part 112 and the rotor coupling part 114 to be described later. It may be a part of the rotation shaft 110 corresponding to.

The rotor coupling part 114 is a part of the rotation shaft 110 on which the rotor 120 is installed, is a part adjacent to the one end 110A of the rotation shaft 110, and may be disposed in the motor space S2.

Specifically, the support part 113 extends in the axial direction L of the rotation shaft 110 from the contact part 1131 in contact with the inner circumferential surface of the rolling bearing 160 to be described later, and the contact part 1131. With respect to the inner circumferential surface 1501 of the bearing housing 150 in the radial direction (R), the gap (G) formed between the inner circumferential surface 1501 of the bearing housing 150 and the outer circumferential surface 1112 of the protrusion 111 It may include a connection portion 1132 spaced apart by the space E.

The rotor 120 may be installed on the rotor coupling portion 114 of the rotation shaft 110. The rotor 120 may be coupled to the rotation shaft 110 so as to surround the outer circumferential surface of the rotation shaft 110, and may be disposed in the motor space S2 where the rotor coupling portion 114 is located.

Specifically, the rotor 120 may include a magnet 121 and a magnet core 122 to which the magnet 121 is mounted. In addition, the rotor 120 may further include a first end plate 123 and a second end plate 124 that are spaced apart from each other in the axial direction L of the rotation shaft 110.

The stator 130 may be installed inside the motor housing 52 and surround the outside of the rotor 120 so as to be spaced apart from the rotor 120 along the radial direction R of the rotation shaft 110. Like 120 ), it may be disposed in the motor space S2 in which the rotor coupling portion 114 of the rotation shaft 110 is located.

Specifically, the stator 130 includes a stator core 131, a coil 132 wound around the stator core 131, and an insulator 133 electrically insulating between the stator core 131 and the coil 132. Can include.

The impeller 140 may be installed on the rotation shaft 110 to be spaced apart from the rotor 120 along the axial direction L of the rotation shaft 110 by a predetermined distance. As described above, the impeller 140 is installed on the impeller coupling portion 112 of the rotation shaft 110 and can rotate together with the rotation of the rotation shaft 110, and the impeller space provided inside the inlet body 51 It can be placed in (S1).

Specifically, the impeller 140 may include a hub 141 and a plurality of blades 142 formed to protrude outward from the outer circumference of the hub 141. Meanwhile, the impeller 140 may be formed of a high-strength synthetic resin material such as polyetheretherketone (PEEK) as a material thereof.

In addition, the impeller 140 may be a four-flow impeller that sucks gas such as air in the axial direction L of the rotation shaft 110 and then discharges it in the centrifugal direction R. That is, the air introduced into the inlet body 51 through the inlet 51A may be guided toward the motor housing 52 along the outer surface of the hub 141 as the blade 142 rotates.

A diffuser 53 may be installed between the impeller 140 and the motor housing 52 to guide air introduced into the inlet body 51 through the impeller 140 toward the motor housing 52. The diffuser 53 may be fastened and fixed to the bearing housing 150 to be described later through fastening members (not shown) such as bolts and nuts. A predetermined space through which gas can flow may be formed between the diffuser 53 and the inlet body 51.

A plurality of diffuser vanes 531 protruding toward the inner surface of the inlet body 51 may be formed on the outer surface of the diffuser 53. The plurality of diffuser vanes 531 may be disposed to be spaced apart at substantially the same distance along the circumferential direction.

The gas introduced into the inlet body 51 through the inlet 51A may be guided to the space between the inlet body 51 and the diffuser 53 by the impeller 140, and the inlet body 51 and the diffuser 53 ) The gas introduced through the gap may be guided to the motor space S2 by the diffuser vanes 531.

The bearing housing 150 has a through hole 151 through which the rotation shaft 110 passes, and may be installed between the rotor 120 and the impeller 140. The bearing housing 150 may surround a part of the rotation shaft 110, that is, the outer peripheral surface of the support part 113.

The bearing housing 150 may be formed integrally with the inlet body 51, but preferably may be manufactured separately from the inlet body 51 and then coupled to the inlet body 51 or the motor housing 52. For example, the bearing housing 150 may be fastened to the inlet body 51 or the motor housing 52 through fastening members such as bolts and screws. When the bearing housing 150 is integrally formed with the inlet body 51 or the motor housing 52, the assembly tolerance may be relatively reduced.

Specifically, the bearing housing 150 surrounds the outer circumferential surface 1602 of the rolling bearing 160, the rolling bearing housing part 152 disposed adjacent to the impeller 140, and the rotation shaft from the rolling bearing housing part 152 The housing connection part 153 that extends in the axial direction (L) of 110 and surrounds the outer circumferential surface (not shown) of the connection part 1132 of the support part 113, and is spaced apart from each other with the connection part 1132 and a space (E). Wow, extending in the axial direction (L) of the rotation shaft 110 from the housing connection part 153, surrounding the outer circumferential surface 1112 of the protruding part 111, and arranged to be spaced apart from each other with the protrusion 111 and the gap (G) And, it may include a gas bearing housing portion 154 disposed to be relatively adjacent to the rotor 120.

In addition, the bearing housing 150 may be made of a material including at least one of aluminum and brass, bronze and nickel-chromium alloy, and in the case of a nickel-chromium alloy, it is preferable that the content of nickel is greater than that of chromium.

In this way, when the bearing housing 150 is made of a material containing at least one of aluminum and brass, bronze, and nickel-chromium alloy, the bearing housing 150 can serve as a housing of a gas bearing, which is a non-contact bearing. have.

That is, when the rotation shaft 110 rotates, a predetermined gap G through which a high-pressure gas can flow may be formed on the inner circumferential surface 1501 of the bearing housing 150 and the outer circumferential surface 1112 of the protrusion 111. In this case, the rotation shaft 110 may be supported in the radial direction R of the rotation shaft 110 by a high-pressure gas flowing through the gap G. Here, the gap G may be formed relatively finely compared to the empty space E formed between the support part 113 and the bearing housing 150.

If current is not applied to the coil 132, that is, when the rotation shaft 110 is in a stopped state before rotation, the gap G may not be uniformly formed along the circumferential direction of the protrusion 111 . That is, when the rotation shaft 110 does not rotate, the rotation shaft 110 may be partially inclined along the axial direction L with respect to the rotation center O.

In this state, when the rotation shaft 110 rotates, a gap G is formed between the gas bearing housing part 154 of the bearing housing 150 and the protrusion 111 of the rotation shaft 110, and the rotation shaft 110 As it rotates at high speed, the gap G may be formed uniformly along the circumferential direction of the protrusion 111. According to this structure, when high-speed rotation of the rotating shaft 110 starts, an environment in which a high-pressure fluid can flow may be created between the gas bearing housing part 154 and the protrusion part 111.

Here, when the rotation shaft 110 is said to rotate at "high speed", "high speed" means a case where the rotation shaft 110 rotates at tens of thousands of RPMs (revolutions per minute), preferably more than 100,000 RPM. can do.

Specifically, when the rotating shaft 110 rotates at high speed, the gas flowing through the gap G may serve as a kind of bearing. That is, the gas flowing through the gap G may function as a journal bearing supporting the rotation shaft 110 in the radial direction R.

That is, since the fluid flowing through the gap G is not in a solid state, it does not cause friction between the inner circumferential surface 1501 of the bearing housing 150 and the outer circumferential surface 1102 of the rotating shaft 110, which is replaced due to wear or damage. It means that the rotating shaft can be stably supported without the use of consumables such as O-rings, which require O-rings.

That is, according to the structure of the protrusion 111 of the rotation shaft 110 and the bearing housing 150 spaced apart from the protrusion 111 with a fine gap (G), the rotating shaft is semi-permanently without periodic replacement or urgent maintenance. Since the 110 can be stably supported, the life of the motor assembly 100 can be significantly extended.

In addition, since the rotation of the rotating shaft 110 can be stably supported without using a lubricant such as grease or oil, which was required for maintenance and operation of the existing bearing structure, the durability of the motor assembly 100 can be improved. .

Hereinafter, for convenience of description, the protrusion 111 and the gas bearing housing 154 of the rotation shaft 110, and the outer peripheral surface 1112 and the gas bearing housing 154 of the protrusion 111 when the rotation shaft 110 rotates. The organic structure of the gap G formed between the inner circumferential surfaces 1501 of) is expressed as "gas bearing (GB)", and specifically, the gas bearing (GB) refers to the gap (G) when the rotation shaft 110 rotates. The description will be continued on the premise that it refers to a component that supports the rotating shaft 110 in the radial direction R through the high-pressure gas flowing in ).

Meanwhile, the rolling bearing 160 may be installed in the bearing housing 150 to support the rotating shaft 110. The rolling bearing 160 includes an inner ring 161 press-fitted to the outer circumferential surface 1102 of the rotating shaft 110, an outer ring 162 press-fitted to the inner circumferential surface 1501 of the bearing housing 150, and an inner ring 161 It may include a ball 163 interposed between the outer ring 162.

In addition, the rolling bearing 160 may be disposed to be closer to the impeller 140 than the protrusion 111 of the rotation shaft 110. That is, the impeller 140, the rolling bearing 160, and the protrusion 111 may be arranged in order along the axial direction L of the rotation shaft 110.

Specifically, since the inner ring 161 of the rolling bearing 160 is press-fitted to the outer peripheral surface 1102 of the rotation shaft 110, the inner ring 161 can also rotate together with the rotation shaft 110 when the rotation shaft 110 rotates. have.

Since the outer ring 162 of the rolling bearing 160 is press-fitted to the inner circumferential surface 1501 of the bearing housing 150, the outer ring 162 remains fixed by the bearing housing 150 even if the rotation shaft 110 rotates. I can.

Meanwhile, the bearing housing 150 may further include a bearing fixing part 155 protruding inward along the radial direction R of the rotation shaft 110. The through hole 151 of the bearing housing 150 is an empty space surrounded by the bearing fixing part 155, and the radius of the through hole 151 is preferably formed larger than the radius of the rotation shaft 110.

This is to prevent friction between the inner ring 161 of the rolling bearing 160 and the bearing housing 150 when the rotation shaft 110 rotates, and the rotation shaft 110 is a rolling bearing installed inside the bearing housing 150 ( 160) and may be supported by the gas bearing GB described above.

The rolling bearing 160 is an example of a contact type bearing, and may support the rotating shaft 110 in the axial direction L and the radial direction R. That is, the inner ring 161 of the rolling bearing 160 is press-fitted to the outer circumferential surface 1102 of the rotating shaft 110, the outer ring 162 is press-fitted to the inner circumferential surface 1501 of the bearing housing 150, and at the same time, the bearing fixing part Since movement in the axial direction L is prevented by 155, the rotation shaft 110 can be supported in the axial direction L and the radial direction R.

Specifically, the inner circumferential surface 1501 of the bearing housing 150 is an inner surface of the bearing housing 150 extending in the axial direction (L), and the bearing fixing part 155 is a bearing housing extending in the radial direction (R) ( 150) may include an inner surface.

In addition, the outer circumferential surface 1602 of the rolling bearing 160 refers to an outer surface extending in the axial direction L of the outer ring 162, which may be press-fitted to the inner circumferential surface 1501 of the bearing housing 150. In this way, by the structure in which the outer ring 162 of the rolling bearing 160 is press-fitted to the inner peripheral surface 1501 of the bearing housing 150, the rolling bearing 160 moves the rotating shaft 110 in the radial direction (R). So that its center of rotation can be fixed.

Meanwhile, of the outer ring 162 of the rolling bearing 160, an outer surface (horizontal surface in FIG. 1) extending in the radial direction R may be in close contact with the inner surface of the bearing fixing part 155. In this way, by a structure in which the outer ring 162 of the rolling bearing 160 is press-fitted to the bearing fixing part 155 of the bearing housing 150, the bearing housing 150 is in the axial direction (L) of the rolling bearing 160 ) Movement can be prevented, and further, movement in the axial direction (L) of the rotation shaft 110 coupled with the inner ring 161 of the rolling bearing 160 can be prevented.

According to this structure, the inner ring 161 of the rolling bearing 160 can rotate together with the rotation of the rotation shaft 110, while the inner ring 161 of the rolling bearing 160 rotates together with the rotation shaft 110 The outer ring 162 of the rolling bearing 160 is maintained in a fixed state by the bearing housing 150, through which the rotating shaft 110 is fixed in the axial direction (L) and the radial direction (R). ) Can be stably supported.

As described above, in the motor assembly 100 according to the present embodiment, two bearings may support the rotation shaft 110 eccentrically. Here, the term'one-side support' means that the two bearings are relatively disposed on the other end 110B side of the rotation shaft 110 around the center of gravity (not shown) of the rotation shaft 110.

Here, the concept opposite to the one-side support is both-side support, which is not shown in the drawing, but in the case of both-side support, one bearing (eg, one rolling bearing 160) is the rotation shaft 110 adjacent to the rotor 120 side. One end (110A) portion of the, the other bearing (eg, another rolling bearing 160) refers to a structure that supports the other end (110B) portion of the rotating shaft 110 adjacent to the impeller 140 side. .

When the rotation shaft 110 is supported on both sides as described above, two bearings and two housings for accommodating the bearings should be provided separately at one end 110A and the other end 110B of the rotation shaft 110. That is, compared to the present embodiment, an additional bearing housing (not shown) is required, and as well as this, a space in which the bearing housing should be installed on the one end 110A side of the rotation shaft 110 is required. Overall, the size and load of the motor assembly 100 are inevitably increased.

On the other hand, unlike the support on both sides, in the motor assembly 100 according to the present embodiment, since the gas bearing (GB) and the rolling bearing 160 are installed inside one bearing housing 150, one bearing housing 150 Since it is only necessary to secure a space in which the motor assembly 100 can be installed, the size and load of the motor assembly 100 can be relatively reduced, and thus the size and weight of the motor assembly 100 can be reduced.

In addition, in the case of supporting both sides, the distance between the bearings supporting the both ends 110A and 110B of the rotating shaft 110 is far, making it difficult to align. As a result, a rotation center error occurs. Noise may occur.

On the other hand, unlike the support on both sides, in the motor assembly 100 according to the present embodiment, a gas bearing (GB) and a rolling bearing 160 are installed inside one bearing housing 150 but the other end of the rotating shaft 110 ( Since it is installed only on the 110B) side, it is possible to minimize the rotation center error between the plurality of bearings installed on the rotation shaft 110, and accordingly, vibration and noise generated when the rotation shaft 110 rotates at high speed can be reduced. Therefore, it is possible to stably support the rotating shaft 110.

In addition, in the case of supporting both sides, consumables such as O-rings should be installed for alignment between bearings supporting both ends 110A and 110B of the rotating shaft 110, but the motor assembly 100 according to the present embodiment The rotation shaft 110 can be stably supported without the use of consumables such as O-rings that need to be replaced due to wear, so that the durability of the motor assembly 100 can be improved as well as the lifespan of the motor assembly 100 can be extended.

Specifically, one bearing housing 150 may accommodate the gas bearing (GB) and the rolling bearing 160, and the gas bearing (GB) and the rolling bearing 160 are seated inside the bearing housing 150. In this state, the rotation shaft 110 may be supported to be rotatable.

As described above, the rolling bearing 160 may perform the function of a thrust and journal bearing capable of supporting the rotating shaft 110 in both the axial direction (L) and the radial direction (R), and , The gas bearing GB may function as a journal bearing capable of supporting the rotating shaft 110 in the radial direction R.

When the rotation shaft 110 rotates at a high speed of tens of thousands of RPM or more as in this embodiment, the ability to support the rotation shaft 110 in the radial direction (R) may be more important than the ability to support the load in the axial direction (L). . In this case, a combination of a gas bearing (GB) supporting the rotating shaft 110 in the radial direction (R) and a rolling bearing 160 supporting the rotating shaft 110 in the radial direction (R) and axial direction (L) at the same time. It may be most desirable to support the rotating shaft 110.

That is, in the present embodiment, a gas bearing (GB) as an example of a non-contact bearing and a rolling bearing 160 as an example of a contact bearing are simultaneously accommodated in one bearing housing 150 and the rotor 120 of the rotating shaft 110 By supporting a portion positioned between the impeller 140 and the rotation shaft 110, the number of parts required to stably support the rotation shaft 110 in the axial direction (L) and the radial direction (R) can be reduced, through which the motor assembly ( 100) can be reduced in size and weight.

FIG. 3 is a cross-sectional view showing a part of the motor assembly shown in FIG. 1 in more detail by separating, and FIG. 4(a) is a cross-sectional view showing a state viewed from above by cutting line II′ of FIG. 3, FIG. 4(b) is a cross-sectional view showing a state viewed from above by cutting line II-II' of FIG. 3.

In the following, among the components of the motor assembly 100 described with reference to FIGS. 3, 4 (a) and 4 (b), the remaining components other than the first coating layer 270 to be described later, for example, a rotating shaft The structures of the 210, the rotor 220, the stator 230, the impeller 240, the bearing housing 250, and the rolling bearing 260 are substantially the same as those of the components shown in FIGS. 1 and 2, Detailed descriptions of these will be omitted.

Referring to FIG. 3, the motor assembly 200 may further include a first coating layer 270 formed on the inner peripheral surface 2501 of the bearing housing 250.

3 and 4(a), a part of the inner circumferential surface 2701 of the first coating layer 270 may contact the outer circumferential surface 2602 of the rolling bearing 260. Specifically, a portion of the inner peripheral surface 2701 of the first coating layer 270 may contact the outer peripheral surface 2602 of the outer ring 262.

In addition, as shown in FIGS. 3 and 4(b), a portion of the inner peripheral surface 2701 of the first coating layer 270 except for a portion in contact with the outer peripheral surface 2602 of the rolling bearing 260 is the rotation shaft 210 ) May be disposed to be spaced apart from each other with a predetermined gap G and the outer circumferential surface 2112 of the protrusion 211. A high-pressure gas may flow through the gap G, and the rotation shaft 210 may be supported in the radial direction R of the rotation shaft 210 by the high-pressure gas flowing through the gap G.

Hereinafter, for convenience of explanation, the protrusion 211 and the first coating layer 270 of the rotation shaft 210, and the outer peripheral surface 2112 and the first coating layer 270 of the protrusion 211 when the rotation shaft 210 rotates. The organic structure of the gap G formed between the inner circumferential surfaces 2701 will be expressed as "gas bearing (GB)", and specifically, the gas bearing (GB) is in the gap (G) when the rotation shaft 210 rotates. The description will be continued on the premise that it refers to a component that supports the rotating shaft 210 in the radial direction R through the flowing high-pressure gas.

Specifically, the first coating layer 270 may occur between the outer circumferential surface 2102 of the rotation shaft 210 and the inner circumferential surface 2501 of the bearing housing 250 when the rotation shaft 210 starts to rotate in a stopped state. It can play a role of buffering friction.

Ideally, the rolling bearing GB starts rotating when the rotating shaft 210 is stationary, and after the rotational speed reaches a steady state, the rotating shaft is rotated through the high-pressure gas flowing through the gap G. 210) can be maximized.

Accordingly, friction may occur between the rotation shaft 210 and the inner peripheral surface 2501 of the bearing housing 250 before the rotation speed of the rotation shaft 210 reaches a normal state or during deceleration in the normal state. When friction occurs between the rotating shaft 210 and the inner circumferential surface 2501 of the bearing housing 250 in this way, there is a concern that not only the temperature rises, but also the portion where the friction occurs is worn, thereby reducing the life of the gas bearing GB.

The first coating layer 270 is coated on the inner circumferential surface 2501 of the bearing housing 250 to reduce the coefficient of friction of the inner circumferential surface 2501 of the bearing housing 250, and even if friction occurs, the bearing housing 250 ) May be made of a material capable of imparting wear resistance to the inner circumferential surface 2501 of the bearing housing 250 so as not to be rapidly deformed.

Specifically, the first coating layer 270 is polytetrafluoroethylene, diamond-like carbon, rubrite, molybdenum disulphide, D10, boron nitride, It may be formed of a material including at least one of ceramic powder, soap, copper, lead, and soft metal.

In detail, the first coating layer 270 is coated on the inner circumferential surface 2501 of the bearing housing 250, and coated on the rolling bearing housing 252 and the connection 253 and the inner circumferential surface 2501 of the gas bearing housing 254. Can be. That is, the first coating layer 270 may be formed to extend in the axial direction L of the rotation shaft 210 inside the bearing housing 250.

In addition, the inner ring 261 of the rolling bearing 260 is press-fitted to the outer peripheral surface 2102 of the rotation shaft 210, and when the rotation shaft 210 rotates, the inner ring 261 may rotate together with the rotation shaft 210. .

Meanwhile, the outer ring 262 of the rolling bearing 260 may be press-fitted to the inner peripheral surface 2701 of the first coating layer 270. Since the bearing housing 250 coated with the first coating layer 270 and the first coating layer 270 remains fixed to the inlet body 51 or the motor housing 52 regardless of the rotation of the rotation shaft 210 , Even if the outer ring 262 of the rolling bearing 260 also rotates, the first coating layer 270 may maintain a fixed state.

In addition, the bearing housing 250 may further include a bearing fixing part 255 protruding inward along the radial direction R of the rotation shaft 210. The through hole 251 of the bearing housing 250 is an empty space surrounded by the bearing fixing part 255, and the radius of the through hole 251 is preferably formed to be larger than the radius of the rotation shaft 210.

This is to prevent friction between the inner ring 261 of the rolling bearing 260 and the bearing housing 250 when the rotation shaft 210 rotates, and the rotation shaft 210 is a rolling bearing installed inside the bearing housing 250 ( 260) and may be supported by the gas bearing GB described above.

The rolling bearing 260 is an example of a contact type bearing and may support the rotation shaft 210 in the axial direction L and the radial direction R. That is, the inner ring 261 of the rolling bearing 260 is press-fitted to the outer peripheral surface 2102 of the rotating shaft 210, and the outer ring 262 is press-fitted to the inner peripheral surface 2701 of the first coating layer 270, and at the same time bearing Since the movement in the axial direction L is prevented by the fixing part 255, the rotation shaft 210 can be supported in the axial direction L and the radial direction R.

Specifically, the inner peripheral surface 2701 of the first coating layer 270 is an inner surface of the first coating layer 270 extending in the axial direction (L), and the bearing fixing portion 255 is a bearing extending in the radial direction (R). It may mean the inner surface of the housing 250.

And, the outer circumferential surface 2602 of the rolling bearing 260 refers to an outer surface extending in the axial direction L of the outer ring 262, which is press-fit into the inner circumferential surface 2701 of the first coating layer 270 as described above. Can be fixed. In this way, by the structure in which the outer ring 262 of the rolling bearing 260 is press-fitted to the inner peripheral surface 2701 of the first coating layer 270, the rolling bearing 260 has the rotation shaft 210 in the radial direction (R). Its center of rotation can be fixed so that it does not move.

Meanwhile, an outer surface (horizontal surface in FIG. 3) of the outer ring 262 of the rolling bearing 260 extending in the radial direction R may be in close contact with the inner surface of the bearing fixing part 255. In this way, by a structure in which the outer ring 262 of the rolling bearing 260 is in close contact with the bearing fixing part 255 of the bearing housing 250, the bearing housing 250 is in the axial direction (L) of the rolling bearing 260 Movement can be prevented, and further, movement in the axial direction (L) of the rotation shaft 210 coupled with the inner ring 261 of the rolling bearing 260 can be prevented.

According to this structure, the inner ring 261 of the rolling bearing 260 can rotate together with the rotation of the rotation shaft 210, while the inner ring 261 of the rolling bearing 260 rotates together with the rotation shaft 210 The outer ring 262 of the rolling bearing 260 is maintained in a fixed state by the bearing housing 250 and the first coating layer 270, through which the rotation shaft 210 is moved in the axial direction (L) and the radial direction (R). It is possible to stably support the rotation of the rotation shaft 210 in a fixed state.

As described above, in the motor assembly 200 according to the present embodiment, two bearings may support the rotating shaft 210 eccentrically. Here, the term'one-side support' means that the two bearings are relatively disposed on the other end 210B side of the rotation shaft 210 around the center of gravity (not shown) of the rotation shaft 210.

Here, the concept opposite to the one-side support is both-side support, which is not shown in the drawing, but in the case of both-side support, one bearing (eg, one rolling bearing 260) is one end of the rotation shaft 210 on the rotor 220 side. The portion 210A and the other bearing (eg, another rolling bearing 260) means a structure supporting the portion of the other end 210B of the rotating shaft 210 adjacent to the impeller 240 side.

When the rotation shaft 210 is supported on both sides as described above, two bearings and two housings accommodating the bearings must be provided separately at one end 210A and the other end 210B of the rotation shaft 210. That is, compared to the present embodiment, an additional bearing housing (not shown) is required, and as well as this, a space in which the bearing housing should be installed on the one end 210A side of the rotating shaft 210 is additionally required. Overall, the size and load of the motor assembly 200 are inevitably increased.

On the other hand, unlike the support on both sides, in the motor assembly 200 according to the present embodiment, since the gas bearing (GB) and the rolling bearing 260 are installed inside one bearing housing 250, one bearing housing 250 Since it is only necessary to secure a space in which this can be installed, it is possible to reduce the size and weight of the motor assembly 200.

In addition, in the case of supporting both sides, the distance between the bearings supporting both ends 210A and 210B of the rotating shaft 210 is long, so alignment is not easy, and a rotation center error occurs. Noise may occur.

On the other hand, unlike the support on both sides, the motor assembly 200 according to the present embodiment has a gas bearing (GB) and a rolling bearing 260 installed inside one bearing housing 250, but the other end of the rotation shaft 210 ( Since it is installed only on the 210B) side, it is possible to minimize the rotation center error between the plurality of bearings installed on the rotation shaft 210, and thus, vibration and noise generated when the rotation shaft 210 rotates at high speed can be reduced. So it can stably support the rotation shaft 210.

In addition, in the case of supporting both sides, consumables such as O-rings should be installed for alignment between bearings supporting both ends 210A and 210B of the rotating shaft 210, but the motor assembly 200 according to the present embodiment Since the rotating shaft 210 can be stably supported without using consumables such as O-rings that need to be replaced due to wear, the durability of the motor assembly 200 can be improved as well as the lifespan thereof can be extended.

Specifically, one bearing housing 250 may accommodate the gas bearing (GB) and the rolling bearing 260, and the gas bearing (GB) and the rolling bearing 260 are seated inside the bearing housing 250. In the state, the rotation shaft 210 may be supported to be rotatable.

As described above, the rolling bearing 260 may perform the function of a thrust and journal bearing capable of supporting the rotation shaft 210 in both the axial direction (L) and the radial direction (R), and the gas bearing (GB) Silver may function as a journal bearing capable of supporting the rotating shaft 210 in the radial direction R.

When the rotation shaft 210 rotates at high speed at a rate of tens of thousands of RPM or more as in this embodiment, the ability to support the rotation shaft 210 in the radial direction (R) may be more important than the ability to support the load in the axial direction (L). . In this case, a combination of a gas bearing (GB) supporting the rotating shaft 210 in the radial direction (R) and a rolling bearing 160 supporting the rotating shaft 110 in the radial direction (R) and axial direction (L) at the same time It may be most desirable to support the rotating shaft 110.

That is, in the present embodiment, a gas bearing (GB) as an example of a non-contact bearing and a rolling bearing 260 as an example of a contact bearing are simultaneously accommodated in one bearing housing 250 and the rotor 220 of the rotation shaft 210 By supporting a portion positioned between the impeller 240 and the rotation shaft 210, the number of parts required to stably support the rotation shaft 210 in the axial direction (L) and the radial direction (R) can be reduced, through which the motor assembly ( 200) can be reduced in size and weight.

5 is a cross-sectional view showing a modified example of the motor assembly shown in FIG. 3, FIG. 6(a) is a cross-sectional view showing a state viewed from above by cutting line III-III' of FIG. 5, and FIG. 6(b) is It is a cross-sectional view showing a state viewed from above by cutting the line IV-IV' of FIG. 5.

In the following, among the components of the motor assembly 300 described with reference to FIGS. 5, 6 (a) and 6 (b), the remaining components other than the first coating layer 370 to be described later, for example, a rotating shaft The structures of the 310, the rotor 320, the stator 330, the impeller 340, the bearing housing 350, and the rolling bearing 360 are substantially the same as those of the components shown in FIGS. 1 and 2, Detailed descriptions of these will be omitted.

5 and 6(b), the motor assembly 300 is formed on a part of the inner circumferential surface 3501 of the bearing housing 350 so as to surround the protrusion 311 along the radial direction R of the rotation shaft 310. The formed first coating layer 370 may be further included.

Specifically, the first coating layer 370 is the inner circumferential surface of the gas bearing housing portion 354 of the bearing housing 350 so as to surround the protrusion 311 of the rotation shaft 310 along the radial direction R of the rotation shaft 310 ( 3501).

Meanwhile, as shown in FIGS. 5 and 6A, a part of the inner peripheral surface 3501 of the bearing housing 350 may contact the outer peripheral surface 3602 of the rolling bearing 360. That is, compared with FIG. 3, the first coating layer 370 may not be interposed between a portion of the inner peripheral surface 3501 of the bearing housing 350 and the outer peripheral surface 3602 of the rolling bearing 360. In other words, a part of the inner circumferential surface 3501 of the bearing housing 350 and the outer circumferential surface 3602 of the rolling bearing 360 may be directly in close contact with each other without the first coating layer 370 interposed therebetween.

In addition, as shown in FIGS. 5 and 6(b), when the rotation shaft 310 is rotated, a high-pressure gas between the inner circumferential surface 3701 of the first coating layer 370 and the outer circumferential surface 3112 of the protrusion 311 A predetermined flowable gap G is formed, and the rotation shaft 310 may be supported in the radial direction R of the rotation shaft 310 by a high-pressure gas flowing in the gap G.

In the following, for convenience of explanation, the protrusion 311 and the first coating layer 370 of the rotation shaft 310, and the outer peripheral surface 3112 and the first coating layer 370 of the protrusion 311 when the rotation shaft 310 rotates. The organic structure of the gap G formed between the inner circumferential surfaces 3701 will be expressed as “gas bearing (GB)”. Specifically, the gas bearing (GB) is in the gap (G) when the rotation shaft 310 rotates. The description will be continued on the premise that it refers to a component that supports the rotating shaft 310 in the radial direction R through the flowing high-pressure gas.

Specifically, the first coating layer 370 may occur between the outer circumferential surface 3102 of the rotation shaft 310 and the inner circumferential surface 3501 of the bearing housing 350 when the rotation shaft 310 starts to rotate in a stationary state. It can play a role of buffering friction.

Ideally, the rolling bearing GB starts rotating when the rotating shaft 310 is stationary, and after the rotational speed reaches a steady state, the rotating shaft ( 310) can maximize the support effect.

Accordingly, friction may occur between the rotation shaft 310 and the inner peripheral surface 3501 of the bearing housing 350 before the rotational speed of the rotation shaft 310 reaches a normal state or during deceleration in the normal state. In this way, when friction occurs between the rotating shaft 310 and the inner circumferential surface 3501 of the bearing housing 350, there is a concern that the temperature rises and the portion where the friction occurs is worn, thereby reducing the life of the gas bearing GB.

The first coating layer 370 is coated on a part of the inner circumferential surface 3501 of the bearing housing 350, that is, the inner circumferential surface 3501 of the gas bearing housing 354 to face the protrusion 311 of the rotation shaft 310 It is possible to reduce the coefficient of friction of the inner circumferential surface 3501 of 350, and wear resistance is provided to the inner circumferential surface 3501 of the bearing housing 350 so that the shape of the bearing housing 350 is not rapidly deformed by wear even if friction occurs. It can be composed of materials that can be done.

Specifically, the first coating layer 370 is polytetrafluoroethylene, diamond-like carbon, rubrite, molybdenum disulphide, D10, boron nitride, It may be formed of a material including at least one of ceramic powder, soap, copper, lead, and soft metal.

In detail, the first coating layer 370 is coated on the inner circumferential surface 3501 of the bearing housing 350, and may be coated on the inner circumferential surface 3501 of the rolling gas bearing housing unit 354. That is, the first coating layer 370 is formed to extend in the axial direction L of the rotation shaft 310 inside the bearing housing 350, and the bearing housing 350 facing the protrusion 311 of the rotation shaft 310 By being formed only on a part of the inner circumferential surface 3501 of, it is possible to effectively prepare for friction between the rotating shaft 310 and the bearing housing 350, and at the same time, a material necessary for coating rather than coating the entire inner circumferential surface 3501 of the bearing housing 350 Can save.

In addition, the inner ring 361 of the rolling bearing 360 is press-fitted to the outer peripheral surface 3102 of the rotating shaft 310, and when the rotating shaft 310 rotates, the inner ring 361 can rotate together with the rotating shaft 310. .

Meanwhile, the outer ring 362 of the rolling bearing 360 may be press-fitted to the inner circumferential surface 3501 of the bearing housing 350. Since the bearing housing 350 remains fixed to the inlet body 51 or the motor housing 52 regardless of the rotation of the rotation shaft 210, the outer ring 362 of the rolling bearing 360 is also the rotation shaft 310 Even if this rotates, it is possible to maintain a fixed state by the bearing housing 350.

In addition, the bearing housing 350 may further include a bearing fixing part 355 protruding inward along the radial direction R of the rotation shaft 310. The through hole 351 of the bearing housing 350 is an empty space surrounded by the bearing fixing part 355, and the radius of the through hole 351 is preferably formed larger than the radius of the rotation shaft 310.

This is to prevent friction between the inner ring 361 of the rolling bearing 360 and the bearing housing 350 when the rotation shaft 310 rotates, and the rotation shaft 310 is a rolling bearing installed inside the bearing housing 350 ( 360) and the gas bearing (GB) described above may be supported.

The rolling bearing 360 is an example of a contact type bearing and may support the rotation shaft 310 in the axial direction L and the radial direction R. That is, the inner ring 361 of the rolling bearing 360 is press-fitted to the outer circumferential surface 3102 of the rotating shaft 310, and the outer ring 362 is press-fitted to the inner circumferential surface 3501 of the bearing housing 350, and at the same time Since movement in the axial direction L is prevented by the top 355, the rotation shaft 310 can be supported in the axial direction L and the radial direction R.

Specifically, the inner circumferential surface 3701 of the first coating layer 370 is the inner surface of the first coating layer 370 extending in the axial direction (L), and the bearing fixing part 355 is a bearing extending in the radial direction (R). It may mean the inner surface of the housing 350.

And, the outer circumferential surface 3602 of the rolling bearing 360 means an outer surface extending in the axial direction L of the outer ring 362, which is press-fitted to the inner circumferential surface 3501 of the bearing housing 350 as described above. Can be. In this way, by a structure in which the outer ring 362 of the rolling bearing 360 is press-fitted to the inner circumferential surface 3501 of the rolling bearing housing part 352, the rolling bearing 360 has a rotation shaft 310 in the radial direction (R) Its rotation center can be fixed so that it does not move.

Meanwhile, of the outer ring 362 of the rolling bearing 360, an outer surface (horizontal surface in FIG. 5) extending in the radial direction R may be in close contact with the inner surface of the bearing fixing part 355. In this way, by a structure in which the outer ring 362 of the rolling bearing 360 is in close contact with the bearing fixing part 355 of the bearing housing 350, the bearing housing 350 is in the axial direction (L) of the rolling bearing 360 Movement can be prevented, and further, movement in the axial direction (L) of the rotation shaft 310 coupled to the inner ring 361 of the rolling bearing 360 can be prevented.

According to this structure, the inner ring 361 of the rolling bearing 360 can rotate together with the rotation of the rotation shaft 310, while the inner ring 361 of the rolling bearing 360 rotates together with the rotation shaft 310 The outer ring 362 of the rolling bearing 360 is maintained in a fixed state by the bearing housing 350, through which the rotating shaft 310 is fixed in the axial direction (L) and the radial direction (R). ) Can be stably supported.

As described above, in the motor assembly 300 according to the present embodiment, two bearings may support the rotating shaft 310 at one side (eccentric). Here, the term'one-side support' means that the two bearings are relatively disposed on the other end 310B side of the rotation shaft 310 with a center of gravity (not shown) of the rotation shaft 310.

Here, the concept opposite to the one-side support is a two-sided support, which is not shown in the drawing, but in the case of two-sided support, one bearing (eg, one rolling bearing 360) is one end of the rotary shaft 310 on the rotor 320 side. The portion 310A and the other bearing (eg, another rolling bearing 360) refers to a structure supporting the portion of the other end 310B of the rotating shaft 310 adjacent to the impeller 340 side.

When the rotation shaft 310 is supported on both sides as described above, two bearings and two housings accommodating the bearings must be separately provided at one end 310A and the other end 310B of the rotation shaft 310. That is, compared to the present embodiment, an additional bearing housing (not shown) is required, and as well as this, a space in which the bearing housing should be installed on the one end 310A side of the rotating shaft 310 is required. Overall, the size and load of the motor assembly 300 are inevitably increased.

On the other hand, unlike the support on both sides, in the motor assembly 300 according to the present embodiment, since the gas bearing (GB) and the rolling bearing 360 are installed inside one bearing housing 350, one bearing housing 350 Since it is only necessary to secure a space in which this can be installed, it is possible to reduce the size and weight of the motor assembly 300.

In addition, in the case of supporting both sides, the distance between the bearings supporting both ends 310A and 310B of the rotation shaft 310 is long, making it difficult to align, and accordingly, a rotation center error occurs. Noise may occur.

On the other hand, unlike the support on both sides, in the motor assembly 300 according to the present embodiment, a gas bearing (GB) and a rolling bearing 360 are installed inside one bearing housing 350 but the other end of the rotation shaft 310 ( Since it is installed only on the 310B) side, it is possible to minimize the rotation center error between the plurality of bearings installed on the rotation shaft 310, and accordingly, vibration and noise generated when the rotation shaft 310 rotates at high speed can be reduced. Therefore, it is possible to stably support the rotating shaft 310.

In addition, in the case of supporting both sides, consumables such as O-rings should be installed for alignment between bearings supporting both ends 310A and 310B of the rotating shaft 310, but the motor assembly 300 according to the present embodiment The rotation shaft 310 can be stably supported without the use of consumables such as O-rings that need to be replaced due to wear, so that the durability of the motor assembly 300 can be improved as well as the lifespan thereof can be extended.

Specifically, one bearing housing 350 may accommodate the gas bearing (GB) and the rolling bearing 360, and the gas bearing (GB) and the rolling bearing 360 are seated inside the bearing housing 350. In the state, the rotation shaft 310 may be supported to be rotatable.

As described above, the rolling bearing 360 may perform the function of a thrust and journal bearing capable of supporting the rotation shaft 310 in both the axial direction (L) and the radial direction (R), and the gas bearing (GB) Silver may perform the function of a journal bearing capable of supporting the rotation shaft 310 in the radial direction (R).

When the rotation shaft 310 rotates at high speed at a rate of tens of thousands of RPM or more as in this embodiment, the ability to support the rotation shaft 310 in the radial direction (R) may be more important than the ability to support the load in the axial direction (L). . In this case, a combination of a gas bearing (GB) supporting the rotating shaft 310 in the radial direction (R) and a rolling bearing 360 supporting the rotating shaft 310 in the radial direction (R) and axial direction (L) at the same time. It may be most preferable to support the rotating shaft 310.

That is, in the present embodiment, a gas bearing (GB), which is an example of a non-contact bearing, and a rolling bearing 360, which is an example of a contact bearing, are simultaneously accommodated in one bearing housing 350, and the rotor 320 of the rotation shaft 310 is By supporting a portion positioned between the impeller 340 and the rotation shaft 310, the number of parts required to stably support the rotation shaft 310 in the axial direction (L) and the radial direction (R) can be reduced, through which the motor assembly ( 300) can be reduced in size and weight.

7 is a cross-sectional view showing another modified example of the motor assembly shown in FIG. 3, and FIG. 8(a) is a cross-sectional view showing a state viewed from above by cutting the line V-V' of FIG. 7, and FIG. 8(b) Is a cross-sectional view showing a state viewed from above by cutting line VI-VI' of FIG. 7.

In the following, among the components of the motor assembly 400 described with reference to FIGS. 7, 8(a) and 8(b), the rest of the components except for the bush 480 and the second coating layer 490 to be described later The structures of the elements, such as the rotating shaft 410, the rotor 420, the stator 430, the impeller 440, the bearing housing 450 and the rolling bearing 460, are similar to the components shown in Figs. Since they are substantially the same, detailed descriptions thereof will be omitted.

Referring to FIG. 7, the motor assembly 400 may further include a bush 480 installed on the inner circumferential surface 4501 of the bearing housing 450. That is, the bush 480 may be press-fit and fixed to the rolling bearing housing portion 452 and the connection portion 453 and the inner peripheral surface 4501 of the gas bearing housing portion 454.

Specifically, the bush 480 may be made of a material including at least one of aluminum and brass, bronze, and nickel-chromium alloy, and in the case of a nickel-chromium alloy, it is preferable that the content of nickel is greater than that of chromium.

As such, when the bush 480 is made of a material including at least one of aluminum and brass, bronze, and nickel-chromium alloy, the bush 480 may serve as a housing of a gas bearing, which is a non-contact bearing.

If the bush 480 is made of a material containing at least one of aluminum, brass, bronze, and nickel-chromium alloy and serves as a housing for a gas bearing, a bearing accommodating the bush 480 and the rolling bearing 460 The housing 450 may be made of plastic. For example, the bearing housing 450 may be formed of a high-strength synthetic resin material such as polyetheretherketone (PEEK).

In this way, when the bearing housing 450 is made of a plastic such as PEEK instead of a metal such as aluminum and brass, bronze and nickel-chromium alloy, the overall weight of the motor assembly 400 is further reduced. I can make it.

At the same time, the bush 480, which has a significantly smaller volume than the bearing housing 450, is formed of a metal material such as aluminum, brass, bronze, and nickel-chromium alloy to serve as a housing of a gas bearing, thereby providing a motor assembly ( Not only can the weight of 400) be reduced, but also the rotation shaft 410 can be stably supported.

That is, when the rotation shaft 410 is rotated, a gap through which high-pressure gas can flow between the inner circumferential surface 4801 of the bush 480 and the outer circumferential surface 4112 of the protrusion 411 (not shown, the second coating layer 490 to be described later than G ) Is formed, and the rotation shaft 410 may be supported in the radial direction R of the rotation shaft 410 by a high-pressure gas flowing in the gap.

In addition, the motor assembly 400 may further include a second coating layer 490 formed on the inner peripheral surface 4801 of the bush 480.

As shown in FIGS. 7 and 8(a), a part of the inner peripheral surface 4901 of the second coating layer 490 may contact the outer peripheral surface 4602 of the rolling bearing 460. Specifically, a portion of the inner peripheral surface 4901 of the second coating layer 490 may contact the outer peripheral surface 4602 of the outer ring 462.

In addition, as shown in FIGS. 7 and 8(b), some of the inner circumferential surface 4901 of the second coating layer 490 except for a part in contact with the outer circumferential surface 4602 of the rolling bearing 460 is the rotation shaft 410 ) May be disposed to be spaced apart from each other with a predetermined gap G and the outer peripheral surface 4112 of the protrusion 411. A high-pressure gas may flow through the gap G, and the rotation shaft 410 may be supported in the radial direction R of the rotation shaft 410 by the high-pressure gas flowing through the gap G.

In the following, for convenience of explanation, the protrusion 411 and the second coating layer 490 of the rotation shaft 410, and the outer peripheral surface 4112 and the second coating layer 490 of the protrusion 411 when the rotation shaft 410 rotates. The organic structure of the gap G formed between the inner circumferential surfaces 4901 is expressed as “gas bearing (GB)”. Specifically, the gas bearing (GB) is in the gap (G) when the rotation shaft 410 rotates. The description will be continued on the premise that it refers to a component that supports the rotating shaft 410 in the radial direction R through the flowing high-pressure gas.

Specifically, the second coating layer 490 is friction that may occur between the outer circumferential surface 4102 of the rotation shaft 410 and the inner circumferential surface 4801 of the bush 480 when the rotation shaft 410 starts to rotate in a stationary state. It can play a role of buffering.

Ideally, the rolling bearing GB starts rotating when the rotating shaft 410 is stationary, and after the rotational speed reaches a steady state, the rotating shaft ( 410) can be maximized.

Accordingly, friction may occur between the rotation shaft 410 and the inner peripheral surface 4801 of the bush 480 before the rotation speed of the rotation shaft 410 reaches a normal state or during deceleration in the normal state. In this way, when friction occurs between the rotating shaft 410 and the inner peripheral surface 4801 of the bush 480, there is a concern that the temperature increases, and the portion where the friction occurs is worn, thereby reducing the life of the gas bearing GB.

The second coating layer 490 is coated on the inner circumferential surface 4801 of the bush 480 to reduce the coefficient of friction of the inner circumferential surface 4801 of the bush 480, and even if friction occurs, the shape of the bush 480 due to wear It may be made of a material capable of imparting wear resistance to the inner circumferential surface 4801 of the bush 480 so as not to be rapidly deformed.

Specifically, the second coating layer 490 is polytetrafluoroethylene, diamond like carbon, rubrite, molybdenum disulphide, D10, boron nitride, It may be formed of a material including at least one of ceramic powder, soap, copper, lead, and soft metal.

In detail, the second coating layer 490 may be coated on the inner circumferential surface 4801 of the bush 480, and the second coating layer 490 extends from the inside of the bush 480 in the axial direction (L) of the rotation shaft 410 It can be formed to be.

In addition, the inner ring 461 of the rolling bearing 460 is press-fitted to the outer circumferential surface 4102 of the rotation shaft 410, and when the rotation shaft 410 rotates, the inner ring 461 may rotate together with the rotation shaft 410. .

Meanwhile, the outer ring 462 of the rolling bearing 460 may be press-fitted to the inner peripheral surface 4901 of the second coating layer 490. The bush 480 coated with the second coating layer 490 and the second coating layer 490 and the bearing housing 450 in which the bush 480 is press-fitted and fixed are the inlet body 51 regardless of the rotation of the rotation shaft 410. B. Since it is kept fixed to the motor housing 52, even if the outer ring 462 of the rolling bearing 460 also rotates, the second coating layer 490, the bush 480, and the bearing housing 450 It can maintain a fixed state.

In addition, the bearing housing 450 may further include a bearing fixing part 455 protruding inward along the radial direction R of the rotation shaft 410. The through hole 451 of the bearing housing 450 is an empty space surrounded by the bearing fixing part 455, and the radius of the through hole 451 is preferably formed larger than the radius of the rotation shaft 410.

This is to prevent friction between the inner ring 461 of the rolling bearing 460 and the bearing housing 450 when the rotation shaft 410 rotates, and the rotation shaft 410 is a rolling bearing installed inside the bearing housing 450 ( It may be supported by 460 and the gas bearing GB described above.

The rolling bearing 460 is an example of a contact type bearing, and may support the rotation shaft 410 in the axial direction L and the radial direction R. That is, the inner ring 461 of the rolling bearing 460 is press-fitted to the outer circumferential surface 4102 of the rotating shaft 410, and the outer ring 462 is press-fitted to the inner circumferential surface 4901 of the second coating layer 490, and at the same time bearing Since the movement in the axial direction (L) is prevented by the fixing part 455, the rotation shaft 410 can be supported in the axial direction (L) and in the radial direction (R).

Specifically, the inner peripheral surface 4901 of the second coating layer 490 is an inner surface of the second coating layer 490 extending in the axial direction (L), and the bearing fixing part 455 is a bearing extending in the radial direction (R). It may mean the inner surface of the housing 450.

And, the outer circumferential surface 4602 of the rolling bearing 460 refers to an outer surface extending in the axial direction L of the outer ring 462, which is press-fit into the inner circumferential surface 4901 of the second coating layer 490 as described above. Can be fixed. In this way, by the structure in which the outer ring 462 of the rolling bearing 460 is press-fitted to the inner peripheral surface 4901 of the second coating layer 490, the rolling bearing 460 has a rotation shaft 410 in the radial direction (R). Its center of rotation can be fixed so that it does not move.

Meanwhile, an outer surface (horizontal surface in FIG. 7) of the outer ring 462 of the rolling bearing 460 extending in the radial direction R may be in close contact with the inner surface of the bearing fixing part 455. In this way, by a structure in which the outer ring 462 of the rolling bearing 460 is in close contact with the bearing fixing part 455 of the bearing housing 450, the bearing housing 450 is in the axial direction (L) of the rolling bearing 460 Movement can be prevented, and further, movement of the rotation shaft 410 coupled with the inner ring 461 of the rolling bearing 460 in the axial direction (L) can be prevented.

According to this structure, the inner ring 461 of the rolling bearing 460 may rotate together with the rotation of the rotation shaft 410, while the inner ring 461 of the rolling bearing 460 rotates together with the rotation shaft 410 The outer ring 462 of the rolling bearing 460 is maintained in a fixed state by the second coating layer 490 and the bush 480 and the bearing housing 450, through which the rotation shaft 410 is moved in the axial direction (L) and It is possible to stably support the rotation of the rotation shaft 410 in a state fixed in the radial direction R.

As described above, in the motor assembly 400 according to the present embodiment, two bearings may support the rotating shaft 410 at one side (eccentric). Here, the term'one-side support' means that the two bearings are relatively disposed on the other end 410B side of the rotation shaft 410 around the center of gravity (not shown) of the rotation shaft 410.

Here, the concept opposite to the one-side support is both-side support, which is not shown in the drawing, but in the case of both-side support, one bearing (for example, one rolling bearing 460) is one end of the rotation shaft 410 on the rotor 420 side. The portion 410A and the other bearing (eg, another rolling bearing 460) refers to a structure supporting the portion of the other end 410B of the rotating shaft 410 adjacent to the impeller 440 side.

When the rotation shaft 410 is supported on both sides as described above, the bearing and the housing accommodating the bearing must be separately provided at one end 410A and the other end 410B of the rotation shaft 410. That is, compared to the present embodiment, an additional bearing housing (not shown) is required, and as well as this, a space in which the bearing housing should be installed on the one end (410A) side of the rotation shaft 410 is additionally required. Overall, the size and load of the motor assembly 400 are inevitably increased.

On the other hand, unlike the support on both sides, in the motor assembly 400 according to the present embodiment, since the gas bearing (GB) and the rolling bearing 460 are installed inside one bearing housing 450, one bearing housing 450 Since it is only necessary to secure a space in which this can be installed, it is possible to reduce the size and weight of the motor assembly 400.

In addition, in the case of supporting both sides, the distance between the bearings supporting both ends (410A, 410B) of the rotation shaft 410 is long, so alignment is not easy. Accordingly, a rotation center error occurs, so vibration and vibration during rotation of the rotation shaft 410 Noise may occur.

On the other hand, unlike the support on both sides, the motor assembly 400 according to the present embodiment has a gas bearing (GB) and a rolling bearing 460 installed inside one bearing housing 450, but the other end of the rotation shaft 410 ( Since it is installed only on the 410B) side, it is possible to minimize the rotation center error between the plurality of bearings installed on the rotation shaft 410, and accordingly, vibration and noise generated when the rotation shaft 410 rotates at high speed can be reduced. It can stably support the rotation shaft 410.

In addition, in the case of supporting both sides, consumables such as O-rings should be installed for alignment between bearings supporting both ends 410A and 410B of the rotating shaft 410, but the motor assembly 400 according to the present embodiment The rotation shaft 410 can be stably supported without the use of consumables such as O-rings that need to be replaced due to wear, so that the durability of the motor assembly 400 can be improved as well as the lifespan thereof.

Specifically, one bearing housing 450 can accommodate the gas bearing (GB) and the rolling bearing 460, and the gas bearing (GB) and the rolling bearing 460 are seated inside the bearing housing 450. In the state, the rotation shaft 410 may be supported to be rotatable.

As described above, the rolling bearing 460 may perform the function of a thrust and journal bearing capable of supporting the rotation shaft 410 in both the axial direction (L) and the radial direction (R), and the gas bearing (GB) Silver may perform the function of a journal bearing capable of supporting the rotation shaft 410 in the radial direction (R).

When the rotation shaft 410 rotates at a high speed of tens of thousands of RPM or more as in this embodiment, the ability to support the rotation shaft 410 in the radial direction (R) may be more important than the ability to support the load in the axial direction (L). . In this case, a combination of a gas bearing (GB) supporting the rotating shaft 410 in the radial direction (R) and a rolling bearing 460 supporting the rotating shaft 410 in the radial direction (R) and axial direction (L) at the same time. It may be most desirable to support the rotation shaft 410.

That is, in the present embodiment, a gas bearing (GB), which is an example of a non-contact bearing, and a rolling bearing 460, which is an example of a contact bearing, are simultaneously accommodated in one bearing housing 450, and the rotor 420 of the rotation shaft 410 By supporting a portion located between the impeller 440 and the rotation shaft 410 in the axial direction (L) and the radial direction (R) it is possible to reduce the number of parts required to stably support the motor assembly ( 400) can be reduced in size and weight.

FIG. 9 is a cross-sectional view showing another modified example of the motor assembly shown in FIG. 3, and FIG. 10(a) is a cross-sectional view showing a state viewed from above by cutting line VII-VII' shown in FIG. 9, and FIG. 10 (b) is a cross-sectional view showing a state viewed from above by cutting line VIII-VIII' shown in FIG. 9.

Hereinafter, among the components of the motor assembly 500 described with reference to FIGS. 9, 10 (a) and 10 (b), the remaining components except for the bush 580 and the second coating layer 590 to be described later The structures of the elements, such as the rotating shaft 510, the rotor 520, the stator 530, the impeller 540, the bearing housing 550, and the rolling bearing 560 are similar to those shown in FIGS. 1 and 2 Since they are substantially the same, detailed descriptions thereof will be omitted.

Referring to FIG. 9, the motor assembly 500 may further include a bush 580 installed on the inner peripheral surface 5501 of the bearing housing 550. That is, the bush 580 may be press-fitted and fixed to the rolling bearing housing portion 552, the connection portion 553, and the inner peripheral surface 5501 of the gas bearing housing portion 554.

Specifically, the bush 580 may be made of a material including at least one of aluminum and brass, bronze, and nickel-chromium alloy, and in the case of a nickel-chromium alloy, it is preferable that the content of nickel is greater than that of chromium.

In this way, when the bush 580 is made of a material including at least one of aluminum, brass, bronze, and nickel-chromium alloy, the bush 580 may serve as a housing of a gas bearing, which is a non-contact bearing.

If the bush 580 is made of a material containing at least one of aluminum, brass, bronze, and nickel-chromium alloy and serves as a housing of a gas bearing, a bearing accommodating the bush 580 and the rolling bearing 560 The housing 550 may be made of plastic. For example, the bearing housing 550 may be formed of a high-strength synthetic resin material such as polyetheretherketone (PEEK).

In this way, when the bearing housing 550 is made of a plastic such as PEEK instead of a metal such as aluminum and brass, bronze, and nickel-chromium alloy, the overall weight of the motor assembly 500 is further reduced. I can make it.

At the same time, the bush 580, which has a significantly smaller volume than the bearing housing 550, is formed of a metal material such as aluminum and brass, bronze, and nickel-chromium alloy to serve as a housing of a gas bearing, thereby providing a motor assembly ( 500) can be reduced in weight and can stably support the rotating shaft 510.

That is, when the rotation shaft 510 rotates, a gap through which a high-pressure gas flows between the inner circumferential surface 5801 of the bush 580 and the outer circumferential surface 5112 of the protrusion 511 (not shown, a second coating layer 590 to be described later than G) ) Is formed, and the rotation shaft 510 may be supported in the radial direction R of the rotation shaft 510 by a high-pressure gas flowing in the gap.

In addition, the motor assembly 500 further includes a second coating layer 590 formed on a portion of the inner circumferential surface 5801 of the bush 580 so as to surround the protrusion 511 along the radial direction R of the rotation shaft 510 can do.

Specifically, the second coating layer 590 may be formed on the inner circumferential surface 5801 of the bush 580 so as to surround the protrusion 511 of the rotation shaft 510 along the radial direction R of the rotation shaft 510.

Meanwhile, as shown in FIGS. 9 and 10A, some of the inner circumferential surface 5801 of the bush 580 may contact the outer circumferential surface 5601 of the rolling bearing 560. That is, compared with FIG. 7, the second coating layer 590 may not be interposed between a portion of the inner peripheral surface 5501 of the bearing housing 550 and the outer peripheral surface 5602 of the rolling bearing 560. In other words, a portion of the inner circumferential surface 5501 of the bearing housing 550 and the outer circumferential surface 5602 of the rolling bearing 560 may be directly in close contact with each other without the second coating layer 590 interposed therebetween.

In addition, as shown in FIGS. 9 and 10 (b), when the rotation shaft 510 rotates, a high-pressure gas between the inner circumferential surface 5901 of the second coating layer 590 and the outer circumferential surface 5112 of the protrusion 511 A predetermined flowable gap G is formed, and the rotation shaft 510 may be supported in the radial direction R of the rotation shaft 510 by a high-pressure gas flowing in the gap G.

Hereinafter, for convenience of explanation, the protrusion 511 and the second coating layer 590 of the rotation shaft 510, and the outer peripheral surface 5112 and the second coating layer 590 of the protrusion 511 when the rotation shaft 510 rotates. The organic structure of the gap (G) formed between the inner circumferential surfaces (5901) will be expressed as "gas bearing (GB)". Specifically, the gas bearing (GB) is in the gap (G) when the rotation shaft 510 rotates. The description will be continued on the premise that it refers to a component that supports the rotating shaft 510 in the radial direction R through the flowing high-pressure gas.

Specifically, the second coating layer 590 is friction that may occur between the outer circumferential surface 5102 of the rotation shaft 510 and the inner circumferential surface 5801 of the bush 580 when the rotation shaft 510 starts to rotate in a stationary state. It can play a role of buffering.

Ideally, the rolling bearing GB starts rotating when the rotating shaft 510 is stationary, and after the rotational speed reaches a steady state, the rotating shaft ( 510) can be maximized.

Accordingly, friction may occur between the rotation shaft 510 and the inner peripheral surface 5801 of the bush 580 before the rotation speed of the rotation shaft 510 reaches a normal state or during deceleration in the normal state. In this way, when friction occurs between the rotation shaft 510 and the inner peripheral surface 5801 of the bush 580, there is a concern that the temperature increases, as well as the friction-producing area wears out, thereby reducing the life of the gas bearing GB.

The second coating layer 590 is coated on the inner circumferential surface 5801 of the bush 580 to reduce the coefficient of friction of the inner circumferential surface 5801 of the bush 580, and even if friction occurs, the shape of the bush 580 due to wear It may be composed of a material capable of imparting wear resistance to the inner peripheral surface 5801 of the bush 580 so as not to be rapidly deformed.

Specifically, the second coating layer 590 is polytetrafluoroethylene, diamond-like carbon, rubrite, molybdenum disulphide, D10, boron nitride, It may be formed of a material including at least one of ceramic powder, soap, copper, lead, and soft metal.

In detail, the second coating layer 590 may be coated on the inner circumferential surface 5801 of the bush 580, and the second coating layer 590 extends in the axial direction L of the rotation shaft 510 inside the bush 580 It is formed so as to be formed only on a part of the inner circumferential surface 5801 of the bush 580 facing the protrusion 511 of the rotation shaft 510, thereby effectively preparing for friction between the rotation shaft 510 and the bush 580 and at the same time bearing It is possible to save a material required for coating rather than coating the entire inner peripheral surface 5501 of the housing 550.

In addition, the inner ring 561 of the rolling bearing 560 is press-fitted to the outer peripheral surface 5102 of the rotation shaft 510, and when the rotation shaft 510 rotates, the inner ring 561 may rotate together with the rotation shaft 510. .

Meanwhile, the outer ring 562 of the rolling bearing 560 may be press-fitted to the inner peripheral surface 5801 of the bush 580. The bearing housing 550 to which the bush 580 and the bush 480 are press-fitted and fixed to the inlet body 51 or the motor housing 52 regardless of the rotation of the rotation shaft 510, so that the rolling bearing Even if the outer ring 562 of the 560 rotates, the bush 580 and the bearing housing 550 may maintain a fixed state.

In addition, the bearing housing 550 may further include a bearing fixing part 555 protruding inward along the radial direction R of the rotation shaft 510. The through hole 551 of the bearing housing 550 is an empty space surrounded by the bearing fixing part 555, and the radius of the through hole 551 is preferably formed larger than the radius of the rotation shaft 510.

This is to prevent friction between the inner ring 561 of the rolling bearing 560 and the bearing housing 550 when the rotation shaft 510 rotates, and the rotation shaft 510 is a rolling bearing installed inside the bearing housing 550 ( 560) and the gas bearing GB described above.

The rolling bearing 560 is an example of a contact type bearing and may support the rotation shaft 510 in the axial direction L and the radial direction R. That is, the inner ring 561 of the rolling bearing 560 is press-fitted to the outer circumferential surface 5102 of the rotating shaft 510, the outer ring 562 is press-fitted to the inner circumferential surface 5801 of the bush 580, and at the same time, the bearing fixing part Movement in the axial direction (L) is prevented by 555, so that the rotation shaft 510 can be supported in the axial direction (L) and in the radial direction (R).

Specifically, the inner peripheral surface 5901 of the second coating layer 590 is an inner surface of the second coating layer 590 extending in the axial direction (L), and the bearing fixing part 555 is a bearing extending in the radial direction (R). It may mean the inner surface of the housing 550.

And, the outer circumferential surface 5602 of the rolling bearing 560 means an outer surface extending in the axial direction L of the outer ring 562, which is press-fitted to the inner circumferential surface 5801 of the bush 580 as described above. I can. In this way, by the structure in which the outer ring 562 of the rolling bearing 560 is press-fitted to the inner circumferential surface 5801 of the bush 580, the rolling bearing 560 does not move the rotation shaft 510 in the radial direction (R). So that its center of rotation can be fixed.

Meanwhile, an outer surface (horizontal surface in FIG. 9) extending in the radial direction R of the outer ring 562 of the rolling bearing 560 may be in close contact with the inner surface of the bearing fixing part 555. In this way, by the structure in which the outer ring 562 of the rolling bearing 560 is in close contact with the bearing fixing part 555 of the bearing housing 550, the bearing housing 550 is in the axial direction (L) of the rolling bearing 560 Movement can be prevented, and further, movement of the rotation shaft 510 coupled with the inner ring 561 of the rolling bearing 560 in the axial direction (L) can be prevented.

According to this structure, the inner ring 561 of the rolling bearing 560 may rotate together with the rotation of the rotation shaft 510, while the inner ring 561 of the rolling bearing 560 rotates together with the rotation shaft 510 The outer ring 562 of the rolling bearing 560 is kept fixed by the bush 580 and the bearing housing 550, and through this, the rotation shaft 510 is fixed in the axial direction (L) and the radial direction (R). In this state, it is possible to stably support the rotation of the rotation shaft 510.

As described above, in the motor assembly 500 according to the present embodiment, two bearings may support the rotating shaft 510 at one side (eccentric). Here, the term'one-side support' means that the two bearings are relatively disposed on the other end 510B side of the rotation shaft 510 with a center of gravity (not shown) of the rotation shaft 510.

Here, the concept opposite to the one-side support is both-side support, which is not shown in the drawing, but in the case of both-side support, one bearing (for example, one rolling bearing 560) is one end of the rotation shaft 510 on the rotor 520 side. The portion 510A and the other bearing (eg, another rolling bearing 560) refers to a structure supporting the portion of the other end 510B of the rotating shaft 510 adjacent to the impeller 540.

When the rotation shaft 510 is supported on both sides as described above, the bearing and the housing accommodating the bearing must be provided at one end 510A and the other end 510B of the rotation shaft 510, respectively. That is, compared to the present embodiment, an additional bearing housing (not shown) is required, and as well as this, a space in which the bearing housing should be installed on the one end 510A side of the rotation shaft 510 is additionally required. Overall, the size and load of the motor assembly 500 are inevitably increased.

On the other hand, unlike the support on both sides, in the motor assembly 500 according to the present embodiment, since the gas bearing (GB) and the rolling bearing 560 are installed inside one bearing housing 550, one bearing housing 550 Since it is only necessary to secure a space in which this can be installed, it is possible to reduce the size and weight of the motor assembly 500.

In addition, in the case of supporting both sides, the distance between the bearings supporting the both ends 510A and 510B of the rotation shaft 510 is long, making it difficult to align, and accordingly, a rotation center error occurs. Noise may occur.

On the other hand, unlike the support on both sides, in the motor assembly 500 according to the present embodiment, a gas bearing (GB) and a rolling bearing 560 are installed inside one bearing housing 550, but the other end of the rotation shaft 510 ( Since it is installed only on the 510B) side, it is possible to minimize the rotation center error between the plurality of bearings installed on the rotation shaft 510, and thus, vibration and noise generated when the rotation shaft 510 rotates at high speed can be reduced. Therefore, it is possible to stably support the rotation shaft 510.

In addition, in the case of supporting both sides, consumables such as O-rings should be installed for alignment between bearings supporting both ends 510A and 510B of the rotating shaft 510, but the motor assembly 500 according to the present embodiment The rotation shaft 510 can be stably supported without the use of consumables such as O-rings that need to be replaced due to wear, so that the durability of the motor assembly 500 can be improved as well as the lifespan of the motor assembly 500 can be extended.

Specifically, one bearing housing 550 can accommodate a gas bearing (GB) and a rolling bearing 560, and the gas bearing (GB) and the rolling bearing 560 are seated inside the bearing housing 550. In the state, the rotation shaft 510 may be supported to be rotatable.

As described above, the rolling bearing 560 may perform the function of a thrust and journal bearing capable of supporting the rotating shaft 510 in both the axial direction (L) and the radial direction (R), and the gas bearing (GB) Silver may perform the function of a journal bearing capable of supporting the rotation shaft 510 in the radial direction (R).

When the rotation shaft 510 rotates at a high speed above tens of thousands of RPMs as in this embodiment, the ability to support the rotation shaft 510 in the radial direction (R) may be more important than the ability to support the load in the axial direction (L). . In this case, a combination of a gas bearing (GB) supporting the rotating shaft 510 in the radial direction (R) and a rolling bearing 560 supporting the rotating shaft 510 in the radial direction (R) and the axial direction (L) at the same time. It may be most desirable to support the rotation shaft 510.

That is, in the present embodiment, a gas bearing (GB) as an example of a non-contact bearing and a rolling bearing 560 as an example of a contact bearing are simultaneously accommodated in one bearing housing 550 and the rotor 520 of the rotation shaft 510 By supporting a portion located between the impeller 540 and the rotation shaft 510 in the axial direction (L) and radial direction (R) it is possible to reduce the number of parts required to stably support the motor assembly ( 500) can be reduced in size and weight.

11 is a flowchart schematically showing a method of manufacturing the motor assembly shown in FIGS. 3 and 5.

Referring to FIGS. 3 and 11 together, first, the inner ring 261 of the rolling bearing 260 is press-fitted to the outer circumferential surface 2102 of the rotation shaft 210, and the rolling bearing 260 may be installed on the rotation shaft 210. (S1101).

Next, the coating layer 270 may be formed by coating the inner circumferential surface 2501 of the bearing housing 250 accommodating the rolling bearing 260 (S1102).

The step of installing the rolling bearing 260 on the rotating shaft 210 (S1101) and the step of coating the coating layer 270 on the inner peripheral surface 2501 of the bearing housing 250 (S1102) are performed by the motor assembly 200 These are steps that can actually be performed separately in the manufacturing stage.

For example, the step of forming the coating layer 270 by coating the inner circumferential surface 2501 of the bearing housing 250 in the reverse order (S1102) is preceded, and thereafter, a rolling bearing 260 is installed on the rotation shaft 210 The step (S1101) may proceed to follow.

In addition, the step of installing the rolling bearing 260 on the rotating shaft 210 (S1101) and the step of forming the coating layer 270 by coating the inner circumferential surface 2501 of the bearing housing 250 (S1102) may be performed simultaneously. have.

After the above-described steps are completed, the rotating shaft 210 and the rolling bearing 260 may be coupled to the bearing housing 250 (S1103). That is, the other end 210B of the rotating shaft 210 in which the rolling bearing 260 is installed passes through the through hole 251 of the bearing housing 250 from the lower side to the upper side, that is, along the axial direction (L). 210) and the rolling bearing 260 may be coupled to the bearing housing 250.

In detail, the step (S1103) of coupling the rotating shaft 210 and the rolling bearing 260 to the bearing housing 250 is fixed by pressing the outer ring 262 of the rolling bearing 260 to the inner circumferential surface 2701 of the coating layer 270 It can be done in a manner

According to the above-described manufacturing method, between the outer circumferential surface 2112 of the protrusion 211 of the rotation shaft 210 protruding along the radial direction R of the rotation shaft 210 and the inner circumferential surface 2701 of the coating layer 270, the rotation shaft 210 ) Can form a predetermined space (G) that can accommodate high-pressure gas.

Meanwhile, referring to FIGS. 5 and 11 together, first, the inner ring 361 of the rolling bearing 360 is press-fitted to the outer circumferential surface 3102 of the rotation shaft 310, and the rolling bearing 360 is installed on the rotation shaft 310. Can be (S1101).

Next, the coating layer 370 may be formed by coating the inner circumferential surface 3501 of the bearing housing 350 accommodating the rolling bearing 360 (S1102). In this case, the coating layer 370 may be formed on a part of the inner circumferential surface 3501 of the bearing housing 350 facing the protrusion 311 of the rotation shaft 310 of the inner circumferential surface 3501 of the bearing housing 350. That is, the coating layer 370 may be formed on the inner peripheral surface 3501 of the gas bearing housing portion 354 of the bearing housing 350.

The step of installing the rolling bearing 360 on the rotating shaft 310 (S1101) and the step of coating the coating layer 370 on the inner circumferential surface 3501 of the bearing housing 350 (S1102) are performed by the motor assembly 300. These are steps that can actually be performed separately in the manufacturing stage.

For example, the step of forming the coating layer 370 by coating the inner circumferential surface 3501 of the bearing housing 350 in the opposite order (S1102) is preceded, and thereafter, the rolling bearing 360 is installed on the rotating shaft 310 The step (S1101) may proceed to follow.

In addition, the step of installing the rolling bearing 360 on the rotating shaft 310 (S1101) and the step of forming the coating layer 370 by coating the inner circumferential surface 3501 of the bearing housing 350 (S1102) may be performed simultaneously. have.

After the above-described steps are completed, the rotating shaft 310 and the rolling bearing 360 may be coupled to the bearing housing 350 (S1103). That is, the other end 310B of the rotating shaft 310 on which the rolling bearing 360 is installed passes through the through hole 351 of the bearing housing 350 from the lower side to the upper side, that is, along the axial direction (L). 310) and the rolling bearing 360 may be coupled to the bearing housing 350.

In detail, the step of coupling the rotation shaft 310 and the rolling bearing 360 to the bearing housing 350 (S1103) is to press-fit the outer ring 362 of the rolling bearing 360 into the inner circumferential surface 3501 of the bearing housing 350 It can be done in a fixed way. That is, the outer ring 362 of the rolling bearing 360 may be press-fitted to the inner circumferential surface 3501 of the rolling bearing housing portion 352 of the bearing housing 350.

According to the above-described manufacturing method, between the outer circumferential surface 3112 of the protrusion 311 of the rotation shaft 310 protruding along the radial direction R of the rotation shaft 310 and the inner circumferential surface 3701 of the coating layer 370, the rotation shaft 310 ) Can form a predetermined space (G) that can accommodate high-pressure gas.

12 is a flow chart schematically illustrating a method of manufacturing the motor assembly shown in FIGS. 7 and 9.

Referring to FIGS. 7 and 12 together, first, the inner ring 461 of the rolling bearing 460 is press-fitted to the outer circumferential surface 4102 of the rotation shaft 410, and the rolling bearing 460 may be installed on the rotation shaft 410. (S1201).

Next, a coating layer 490 may be formed by coating the inner circumferential surface 4801 of the bush 480 accommodating the rolling bearing 460 (S1202).

The step of installing the rolling bearing 460 on the rotating shaft 410 (S1201) and the step of coating the coating layer 490 on the inner circumferential surface 4801 of the bush 480 (S1102) include manufacturing the motor assembly 400 In fact, these steps can be performed separately.

For example, the step of forming the coating layer 490 by coating the inner circumferential surface 4801 of the bush 480 in the reverse order (S1202) is preceded, and thereafter, the rolling bearing 460 is installed on the rotating shaft 410. Step S1201 may proceed to follow.

In addition, the step of installing the rolling bearing 460 on the rotating shaft 410 (S1201) and the step of forming the coating layer 490 by coating the inner circumferential surface 4801 of the bush 480 (S1202) may be simultaneously performed. .

After the above-described steps are completed, the bush 480 may be press-fitted and fixed to the inner circumferential surface 4501 of the bearing housing 450 (S1203).

Thereafter, the rotation shaft 410 and the rolling bearing 460 may be coupled to the inner circumferential surface 4801 of the bush 480 (S1204) (that is, the rotation shaft 410 in which the rolling bearing 460 is installed is attached to the bush 480). May be coupled to the bearing housing 450 is coupled). Specifically, the other end 410B of the rotating shaft 410 on which the rolling bearing 460 is installed passes through the through hole 451 of the bearing housing 450 from the lower side to the upper side, that is, along the axial direction (L). The 2410 and the rolling bearing 460 may be coupled to the bush 480.

In detail, the step of coupling the rotating shaft 410 and the rolling bearing 460 to the bush 480 (S1204) is to press-fit the outer ring 462 of the rolling bearing 460 to the inner circumferential surface 4801 of the bush 480. It can be done in a way.

According to the above-described manufacturing method, the rotation shaft 410 between the outer circumferential surface 4112 of the protrusion 411 of the rotation shaft 410 protruding along the radial direction R of the rotation shaft 410 and the inner circumferential surface 4901 of the coating layer 490. ) Can form a predetermined space (G) that can accommodate high-pressure gas.

Meanwhile, referring to FIGS. 9 and 12 together, first, the inner ring 561 of the rolling bearing 560 is press-fitted to the outer circumferential surface 5102 of the rotation shaft 510, and the rolling bearing 560 is installed on the rotation shaft 510. Can be (S1201).

Next, a coating layer 590 may be formed by coating the inner peripheral surface 5801 of the bush 580 accommodating the rolling bearing 560 (S1202).

In this case, the coating layer 590 may be formed on a portion of the inner peripheral surface 5501 of the bearing housing 550 facing the protrusion 511 of the rotation shaft 510 among the inner peripheral surface 5501 of the bearing housing 550. That is, the coating layer 590 may be formed on the inner peripheral surface 5501 of the gas bearing housing portion 554 of the bearing housing 550.

The step of installing the rolling bearing 560 on the rotating shaft 510 (S1201) and the step of coating the coating layer 590 on the inner circumferential surface 5801 of the bush 580 (S1202) include manufacturing the motor assembly 500 In fact, these steps can be performed separately.

For example, the step of forming the coating layer 590 by coating the inner circumferential surface 5501 of the bearing housing 550 in the reverse order (S1202) is preceded, and thereafter, a rolling bearing 560 is installed on the rotating shaft 510 The step (S1201) may proceed to follow.

In addition, the step of installing the rolling bearing 560 on the rotating shaft 510 (S1201) and the step of forming the coating layer 590 by coating the inner circumferential surface 5801 of the bush 580 (S1202) may be performed simultaneously. .

After the above-described steps are completed, the bush 580 may be press-fitted and fixed to the inner peripheral surface 5501 of the bearing housing 550 (S1203).

Thereafter, the rotation shaft 510 and the rolling bearing 560 may be coupled to the inner circumferential surface 5801 of the bush 580 (S1203) (that is, the rotation shaft 510 on which the rolling bearing 560 is installed is attached to the bush 580). May be coupled to the bearing housing 550 is coupled). Specifically, the other end 510B of the rotating shaft 510 on which the rolling bearing 560 is installed passes through the through hole 551 of the bearing housing 550 from the lower side to the upper side, that is, along the axial direction (L). The 510 and the rolling bearing 560 may be coupled to the bush 580.

In detail, the step of coupling the rotating shaft 510 and the rolling bearing 560 to the bush 580 (S1204) is a press-fitting fixing of the outer ring 562 of the rolling bearing 560 to the inner circumferential surface 5801 of the bearing bush 580 It can be done in a way that makes it happen. That is, the outer ring 562 of the rolling bearing 560 may be press-fitted to the inner peripheral surface 5501 of the rolling bearing housing portion 552 of the bearing housing 550.

According to the above-described manufacturing method, the rotation shaft 510 between the outer peripheral surface 5112 of the protrusion 511 of the rotation shaft 510 protruding along the radial direction R of the rotation shaft 510 and the inner peripheral surface 5901 of the coating layer 590 ) Can form a predetermined space (G) that can accommodate high-pressure gas.

Those of ordinary skill in the technical field related to the present embodiment will appreciate that it may be implemented in variously modified forms without departing from the essential characteristics of the above-described substrate. Therefore, the disclosed embodiments should be considered from an illustrative point of view rather than a limiting point of view. The scope of the embodiments of the present invention is shown in the claims rather than the foregoing description, and all differences within the scope equivalent thereto should be construed as being included in the embodiments of the present invention.

51: inlet body 130: stator
52: motor housing 140: impeller
53: diffuser 141: hub
53v: diffuser vane 142: blade
100: motor assembly 150: bearing housing
110: rotation shaft 151: through hole
111: protrusion 152: rolling bearing housing part
112: impeller coupling portion 153: housing connection
113: support 154: gas bearing housing
1131: contact portion 155: bearing fixing portion
1132: connection 160: rolling bearing
114: rotor coupling portion 161: inner ring
120: rotor 162: outer ring
121: magnet 163: ball
122: magnet core 170, 270, 370: first coating layer
123: first end plate 480, 580: bush
124: second end plate 490, 590: second coating layer

Claims (22)

Rotating shaft;
A rotor installed on the rotating shaft;
A stator surrounding the outer side of the rotor so as to be spaced apart from the rotor along a radial direction of the rotation shaft;
An impeller installed on the rotation shaft to be spaced apart from the rotor by a predetermined distance along the axial direction of the rotation shaft;
A bearing housing provided with a through hole through which the rotation shaft passes, and installed between the rotor and the impeller; And
Includes; a rolling bearing installed in the bearing housing to support the rotation shaft,
The rotation shaft includes a protrusion protruding toward an outer radial direction of the rotation shaft,
The bearing housing is spaced apart from an outer peripheral surface of the protrusion by a predetermined gap to surround the protrusion, and the rotation shaft is supported in the radial direction by a high-pressure gas flowing through the gap. The method of claim 1,
The motor assembly, characterized in that the impeller, the rolling bearing, and the protrusion are arranged in order along the axial direction of the rotation shaft. The method of claim 1,
Motor assembly further comprising a first coating layer formed on the inner peripheral surface of the bearing housing. The method of claim 3,
The first coating layer is polytetrafluoroethylene, diamond like carbon, rubrite, molybdenum disulphide, D10, boron nitride, ceramic powder. ), soap, copper, lead, and a soft metal. The method of claim 3,
The motor assembly, characterized in that the outer peripheral surface of the rolling bearing is in contact with a part of the first coating layer. The method of claim 5,
The gap, the motor assembly, characterized in that formed between the first coating layer and the outer peripheral surface of the protrusion. The method of claim 3,
The motor assembly, characterized in that the outer peripheral surface of the rolling bearing is in contact with the inner peripheral surface of the bearing housing. The method of claim 7,
The first coating layer is formed on a portion of the inner peripheral surface of the rolling bearing housing facing the outer peripheral surface of the protrusion, and the gap is formed between the first coating layer and the outer peripheral surface of the protrusion. The method of claim 1,
The rotating shaft,
An impeller coupling portion in which the impeller is installed,
A support part facing the bearing housing along the radial direction of the rotation shaft,
A motor assembly comprising a rotor coupling portion to which the rotor is installed. The method of claim 9,
The support part,
A contact portion in contact with the inner circumferential surface of the rolling bearing,
It extends in the axial direction of the rotation shaft from the contact part, and is wider than the gap formed between the inner circumferential surface of the bearing housing and the outer circumferential surface of the protrusion with respect to the inner circumferential surface of the bearing housing based on the radial direction of the rotation shaft. A motor assembly comprising a connection that is spaced apart from each other. The method of claim 10,
The bearing housing,
A rolling bearing housing portion surrounding the outer circumferential surface of the rolling bearing and disposed relatively adjacent to the impeller,
A housing connection part extending from the rolling bearing housing part in the axial direction of the rotation shaft, surrounding an outer peripheral surface of the connection part, and spaced apart from each other with the connection part and the space,
It includes a gas bearing housing part extending from the housing connection part in the axial direction of the rotation shaft, surrounding the outer circumferential surface of the protruding part, and disposed to be spaced apart from each other with the protrusion and the gap, and disposed relatively adjacent to the rotor. , Motor assembly. The method of claim 1,
The rolling bearing,
An inner ring press-fitted to the outer circumferential surface of the rotating shaft,
An outer ring press-fitted to the inner peripheral surface of the bearing housing, and
A motor assembly comprising a ball interposed between the inner ring and the outer ring. The method of claim 12,
When the rotation shaft rotates,
The inner ring of the rolling bearing rotates together with the rotation shaft,
The motor assembly, characterized in that the outer ring of the rolling bearing is maintained in a fixed state by the bearing housing. The method of claim 13,
The bearing housing includes a bearing fixing part protruding inwardly along the radial direction of the rotation shaft,
The through hole is an empty space surrounded by the bearing fixing part,
The bearing fixing part prevents the outer ring of the rolling bearing from moving toward the impeller along the axial direction of the rotation shaft. The method of claim 1,
The bearing housing includes at least one of aluminum and brass, bronze and nickel-chromium alloy,
The nickel-chromium alloy is a motor assembly, characterized in that the content of nickel is greater than the content of chromium. The method of claim 1,
Further comprising a bush installed on the inner peripheral surface of the bearing housing,
The bush includes at least one of aluminum and brass, bronze and nickel-chromium alloy,
When the rotation shaft is rotated, a gap is formed between the inner circumferential surface of the bush and the outer circumferential surface of the protrusion, and the rotation shaft is supported in the radial direction of the rotation shaft by the high pressure gas flowing in the gap. It characterized in that the motor assembly. The method of claim 16,
The motor assembly further comprising a second coating layer formed on the inner peripheral surface of the bush. The method of claim 17,
The second coating layer is polytetrafluoroethylene, diamond like carbon, lubrite, molybdenum disulphide, D10, boron nitride, ceramic powder. ), soap, copper, lead, and a soft metal. The method of claim 17,
Part of the inner peripheral surface of the second coating layer is in contact with the outer peripheral surface of the rolling bearing,
When the rotation shaft is rotated, a predetermined gap is formed between another part of the inner circumferential surface of the second coating layer and the outer circumferential surface of the protrusion, and the rotation shaft is formed by the high-pressure gas flowing in the gap. Motor assembly, characterized in that supported in the radial direction of the rotation shaft. The method of claim 17,
The second coating layer is formed on a portion of the inner circumferential surface of the bush to surround the protrusion along the radial direction of the rotation shaft,
Another part of the inner peripheral surface of the bush is in contact with the outer peripheral surface of the rolling bearing,
When the rotation shaft rotates, a predetermined gap is formed between the inner circumferential surface of the second coating layer and the outer circumferential surface of the protrusion, and the rotation shaft is formed by the high-pressure gas flowing through the gap. Motor assembly, characterized in that supported in the radial direction. Press-fitting the inner ring of the rolling bearing to the outer peripheral surface of the rotating shaft;
Forming a coating layer by coating an inner circumferential surface of a bearing housing accommodating the rolling bearing; And
Including; installing the rotating shaft and the rolling bearing in the bearing housing; Including,
The step of coupling the rotation shaft and the rolling bearing to the bearing housing,
Press-fit and fix the outer ring of the rolling bearing to the inner circumferential surface of the coating layer,
A method of manufacturing a motor assembly, characterized in that a predetermined gap is formed between the outer circumferential surface of the protrusion of the rotation shaft and the inner circumferential surface of the coating layer protruding along the radial direction of the rotation shaft, allowing high-pressure gas to flow when the rotation shaft is rotated. Press-fitting the inner ring of the rolling bearing to the outer peripheral surface of the rotating shaft;
Forming a coating layer by coating an inner circumferential surface of the bush accommodating the rolling bearing;
Installing the bush on the inner peripheral surface of the bearing housing; And
Including; installing the rotating shaft and the rolling bearing in the bearing housing; Including,
The step of installing the rotating shaft and the rolling bearing in the bearing housing,
Press-fit and fix the outer ring of the rolling bearing to the inner circumferential surface of the coating layer,
A method of manufacturing a motor assembly, characterized in that a predetermined space is formed between the outer circumferential surface of the protrusion of the rotation shaft and the inner circumferential surface of the coating layer protruding along the radial direction of the rotation shaft, allowing high-pressure gas to flow when the rotation shaft is rotated.

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