EP4647580A1

EP4647580A1 - Compressor and refrigeration cycle apparatus

Info

Publication number: EP4647580A1
Application number: EP25174730.9A
Authority: EP
Inventors: Katsumi Kato; Yoshitomo Tsuka
Original assignee: Daikin Industries Ltd
Current assignee: Daikin Industries Ltd
Priority date: 2024-05-10
Filing date: 2025-05-07
Publication date: 2025-11-12
Also published as: JP2025171853A

Abstract

Provided are a compressor in which a bearing housing can be suitably fixed to a casing without using a welding pin and a refrigeration cycle apparatus using the compressor. A compressor (100) includes a casing (110), a bearing housing (130), an electric motor (140), and a support (161). The casing (110) has a tubular shape. The bearing housing (130) and the electric motor (140) are fixed in the casing (110) so as to be separated from each other in an axial direction of the casing (110). The support is disposed in a first space (S1) located between the bearing housing (130) and the electric motor (140). The bearing housing is fixed to the casing by interference fitting. The support is fixed to the casing (110) by welding and supports the bearing housing (130).

Description

BACKGROUND OF THE INVENTION

Field of the Invention

The present disclosure relates to a compressor and a refrigeration cycle apparatus.

Description of the Related Art

In a compressor disclosed in Patent Literature 1 ( JP H6-66267 A ), a bearing housing is fixed to a casing by plug welding with a welding pin.

SUMMARY OF THE INVENTION

When the bearing housing is fixed to the bearing housing with the welding pin, in the welding pin expanded by heat at a time of welding, a distal end of a tooth shape formed on an outer periphery is plastically deformed, a press-fit holding force is reduced, and the bearing housing cannot be suitably fixed to the casing in some cases.
An object of the present application is to provide a compressor in which a bearing housing can be suitably fixed to a casing without using a welding pin and to provide a refrigeration cycle apparatus using the compressor.
This aim is achieved by the compressor according to the corresponding appended claims.
The present disclosure regards a compressor. The compressor comprises a casing. The casing is elongated in an axial direction (along a longitudinal axis). In an example, the casing has a tubular shape.
The compressor comprises an electric motor. The electric motor is accommodated in the casing. The electric motor is fixed to the casing.
The compressor comprises a bearing housing. The bearing housing may be accommodated in the casing. The bearing housing is fixed to the casing.
The bearing housing and the electric motor are separated (spaced) from each other in the axial direction. The casing includes a first space located between the bearing housing and the electric motor.
The compressor comprises a support. The support is disposed in the first space. In an example, the support is configured for supporting the fluid guide.
In an example, the bearing housing is fixed to the casing by interference fitting.
In an example, the support is fixed to the casing by welding. The support is configured to support the bearing housing.
In an example, the compressor comprises a fluid guide. In an example, the fluid guide is located within the casing, preferably in the first space. The fluid guide is configured to guide a fluid flowing into the first space to an outer periphery of the electric motor.
The compressor comprises a compression mechanism and an electric motor. The compression mechanism and the electric motor are both accommodated in the casing.
The compressor, according to a first aspect (the term "aspect", in the present application, is used to mean an aspect of the disclosure; this language, per se, should not be construed to exclude that different aspects may be present together in the compressor), includes a casing, a bearing housing, an electric motor, and a support. The casing has a tubular shape. The bearing housing and the electric motor are fixed in the casing so as to be separated from each other in an axial direction of the casing. The support is disposed in a first space located between the bearing housing and the electric motor. The bearing housing is fixed to the casing by interference fitting. The support is fixed to the casing by welding and supports the bearing housing.
The bearing housing of the compressor is fixed to the casing by interference fitting, and is supported by the support fixed to the casing by welding. Therefore, in the compressor, the bearing housing can be suitably fixed to the casing without using a welding pin. According to a second aspect, the support is fixed to the bearing housing with a bolt. In the compressor, with the bolt, the support is easily fixed to the bearing housing.
According to a third aspect, the support includes a stay extending along a surface of the bearing housing facing the first space. The stay is fixed to the bearing housing with a bolt.
According to a fourth aspect, the support is fixed to the bearing housing by press fitting.
In the compressor, by press fitting, the support is firmly fixed to the bearing housing.
According to a fifth aspect, the support includes a cylindrical portion whose outer peripheral surface faces an inner peripheral surface of the casing.
In the compressor, the support, which has the cylindrical portion, is easily assembled to the casing.
According to a sixth aspect, the compressor may further include an oil return guide and a gas guide that are disposed in the first space and guide a fluid flowing between the bearing housing and the electric motor to an outer periphery of the electric motor. The oil return guide and the gas guide are fixed to the support by spot welding.
In the compressor, since a fluid guide guides a refrigerant and a lubricating oil discharged from the compression mechanism, a lubricating oil included in the refrigerant is prevented from scattering due to a rotation of a rotor of the electric motor.
According to a seventh aspect, a position at which the support is welded to the casing is closer to the electric motor than a position at which the bearing housing is in an interference fit with the casing.
In the compressor, a load generated in the compression mechanism along with operation can be received by the bearing housing and the support. Therefore, the compressor can reduce a moment acting on a position at which the bearing housing is fixed to (in an interference fit with) the casing during operation as compared in a case where the support is not provided.
According to an eighth aspect, a plate thickness of a portion of the support welded to the casing is thinner than a plate thickness of a corresponding portion of the casing.
According to a ninth aspect, the support is fixed to the casing by plug welding.
According to a tenth aspect, the support includes a material having better weldability than the bearing housing.
In the compressor, the support is firmly fixed to the bearing housing by welding.
According to an eleventh aspect, the compressor may comprise a carbon dioxide refrigerant.
In a case where carbon dioxide having a high pressure at room temperature is used as the refrigerant, the casing of the compressor is formed to have a plate thickness thicker than a plate thickness of a compressor used for another refrigerant in order to secure pressure resistance. In this case, since it is necessary to increase an amount of heat input, the welding pin greatly expands at a time of welding, a distal end of a tooth shape formed on an outer periphery is plastically deformed, a press-fit holding force is reduced, and the bearing housing cannot be suitably fixed to the casing in some cases.
The bearing housing of the compressor is fixed to the casing by interference fitting, and is supported by the support fixed to the casing by welding. Therefore, in the compressor, the bearing housing can be suitably fixed to the casing even in a case where carbon dioxide is used for the refrigerant.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic configuration diagram of a refrigeration cycle apparatus 1 including a compressor 100;
FIG. 2 is a longitudinal sectional view of the compressor 100 taken along line A-A' (see FIG. 4);
FIG. 3 is a longitudinal sectional view of the compressor 100 taken along line B-B' (see FIG. 4);
FIG. 4 is a cross sectional view of the compressor 100 taken along line C-C' (see FIG. 2);
FIG. 5 is an enlarged sectional view of a D portion (see FIG. 2);
FIG. 6 is an enlarged sectional view of an E portion (see FIG. 3);
FIG. 7 is a perspective view of a fluid guide assembly 160;
FIG. 8 is a perspective view of a support 161;
FIG. 9A is a perspective view of an oil return guide 162;
FIG. 9B is a perspective view of the oil return guide 162;
FIG. 10A is a perspective view of a gas guide 163; and
FIG. 10B is a perspective view of the gas guide 163.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

(1) Configuration of refrigeration cycle apparatus 1

A compressor 100 according to the present embodiment is a high-pressure dome-type scroll compressor. The compressor 100 is used in a refrigeration cycle apparatus, for example.
FIG. 1 is a schematic configuration diagram of a refrigeration cycle apparatus 1 including the compressor 100. The refrigeration cycle apparatus 1 is an air conditioner, and performs cooling and heating of a room in a building or the like by performing a vapor compression refrigeration cycle. The refrigeration cycle apparatus 1 includes a refrigerant circuit 6 including the compressor 100. The refrigerant circuit 6 is configured by connecting a heat source unit 2 and a utilization unit 3 via a first connection pipe 4 and a second connection pipe 5. In the refrigerant circuit 6, carbon dioxide is sealed as a refrigerant.
The compressor 100 sucks the refrigerant in the refrigerant circuit 6, compresses the refrigerant to a predetermined pressure, and discharges the refrigerant. The compressor 100 discharges the compressed refrigerant to the refrigerant circuit 6, and thus, the refrigerant circulates in the refrigerant circuit 6.
The heat source unit 2 is installed outdoors. The heat source unit 2 mainly accommodates devices constituting the refrigerant circuit 6. The refrigerant circuit 6 accommodated in the heat source unit 2 includes the compressor 100, a four-way switching valve 9, a heat source heat exchanger 8, an expansion valve 7, a first shutoff valve 11, and a second shutoff valve 12.
The utilization unit 3 is installed indoors. The utilization unit 3 mainly includes a utilization heat exchanger 10 constituting the refrigerant circuit 6.
The first connection pipe 4 and the second connection pipe 5 are pipes through which the refrigerant flows. One end of the first connection pipe 4 is connected to the first shutoff valve 11 of the heat source unit 2. The other end of the first connection pipe 4 is connected to one end of the utilization heat exchanger 10 of the utilization unit 3. One end of the second connection pipe 5 is connected to the second shutoff valve 12 of the heat source unit 2. The other end of the second connection pipe 5 is connected to the other end of the utilization heat exchanger 10 of the utilization unit 3.
In the present embodiment, the refrigeration cycle apparatus 1 in which one utilization unit 3 is connected to one heat source unit 2 is illustrated. Alternatively, a so-called multi-type refrigeration cycle apparatus in which a plurality of utilization units is connected to one heat source unit may be used.

(2) Configuration of compressor 100

FIG. 2 is a longitudinal sectional view of the compressor 100 taken along line A-A' (see FIG. 4). FIG. 3 is a longitudinal sectional view of the compressor 100 taken along line B-B' (see FIG. 4). FIG. 4 is a cross sectional view of the compressor 100 taken along line C-C' (see FIG. 2). FIG. 5 is an enlarged sectional view of a D portion (see FIG. 2). FIG. 6 is an enlarged sectional view of an E portion (see FIG. 3).
As illustrated in FIG. 2, the compressor 100 mainly includes a casing 110, a compression mechanism 120, a bearing housing 130, an electric motor 140, a crankshaft 150, a fluid guide assembly 160, a suction pipe 180, and a discharge pipe 190.
Each direction of "up" and "down" used in the following description corresponds to a direction indicated by an arrow in FIG. 2.

(2-1) Casing 110

The casing 110 accommodates the compression mechanism 120, the bearing housing 130, the electric motor 140, the crankshaft 150, and the fluid guide assembly 160.
The casing 110 has a tubular shape. The casing 110 includes a substantially cylindrical casing body 112, a bowl-shaped upper wall 111 welded to an upper end of the casing body 112 such that a joint portion has airtightness, and a bowl-shaped bottom wall 113 welded to a lower end of the casing body 112 such that a joint portion has airtightness. The casing 110 is installed such that an axial direction of the casing body 112 is along a vertical direction (up-down direction).
The casing 110 is molded with a rigid member that is less likely to be deformed and damaged when pressure and temperature change inside and outside the casing 110.
As described above, the refrigerant sealed in the refrigerant circuit 6 includes carbon dioxide. Therefore, the casing 110 of the compressor 100, which is required to have high pressure resistance, is designed to have a larger plate thickness than a casing of a compressor used for another refrigerant. Specifically, a plate thickness T1 (see FIG. 3) of the casing body 112 is, for example, 10 mm or more and 12 mm or less.

(2-2) Compression mechanism 120

The compression mechanism 120 compresses the sucked refrigerant to a predetermined pressure. The compression mechanism 120 is disposed on an inner side of the casing body 112. The compression mechanism 120 includes a fixed scroll 121 and an orbital scroll 122.

(2-2-1) Fixed scroll 121

The fixed scroll 121 includes a first end plate 121a, a first wrap 121b, and a first outer peripheral wall 121c.
The first end plate 121a has a substantially circular plate shape, and is disposed to have a main surface orthogonal to the up-down direction.
The first wrap 121b and the first outer peripheral wall 121c are wall surfaces protruding downward from the first end plate 121a. Specifically, the first wrap 121b is a wall surface whose distal end surface exhibits a spiral shape (involute shape) extending from a vicinity of a center of the first end plate 121a toward an outer peripheral side in a plan view of the first end plate 121a. The first outer peripheral wall 121c is a wall surface surrounding an outer periphery of the first wrap 121b. A distal end surface of the first wrap 121b and a distal end surface of the first outer peripheral wall 121c are substantially flush with each other.
The first outer peripheral wall 121c has a suction hole 121d that causes a compression chamber 124 to be described later and the outside of the compression chamber 124 to communicate with each other. A groove-shaped first communication passage 121f that causes an upper side and a lower side of the compression mechanism 120 to communicate with each other is provided on an outer peripheral surface of the first outer peripheral wall 121c.
A discharge hole 121e that causes the compression chamber 124 and the outside of the compression chamber 124 to communicate with each other is provided in a central portion of the first end plate 121a.

(2-2-2) Orbital scroll 122

The orbital scroll 122 includes a second end plate 122a, a second wrap 122b, and a second bearing 123.
The second end plate 122a has a substantially circular plate shape, and is disposed to have a main surface orthogonal to the up-down direction.
The second wrap 122b is a wall surface protruding upward from the second end plate 122a. Specifically, the second wrap 122b is a wall surface whose distal end surface exhibits a spiral shape (involute shape) extending from a vicinity of a center of the second end plate 122a toward an outer peripheral side in a plan view of the second end plate 122a. The second bearing 123 has a substantially cylindrical shape and protrudes downward from the center of the second end plate 122a.
The first wrap 121b and the second wrap 122b mesh with each other, and then, the fixed scroll 121 and the orbital scroll 122 form the compression chamber 124 surrounded by the first end plate 121a, the first wrap 121b, the second end plate 122a, and the second wrap 122b.
The orbital scroll 122 is engaged with the bearing housing 130 via an Oldham's coupling (not illustrated) to regulate rotation.

(2-3) Bearing housing 130

The bearing housing 130 partitions the inside of the casing 110 into a first space S1 located below the bearing housing 130 and a second space S2 located above the bearing housing 130. The bearing housing 130 is disposed below the compression mechanism 120 on the inner side of the casing body 112. The bearing housing 130 has a dish-like shape with a recessed center, and is provided with an annular portion 131, a recess 132, a first bearing 133, a first oil return oil path 132a, and a second oil return oil path 132b. The bearing housing 130 is fixed to the casing 110.

(2-3-1) Annular portion 131

An outer peripheral surface of the annular portion 131 is formed substantially along an inner peripheral surface of the casing body 112. An upper end of the annular portion 131 supports the fixed scroll 121 from below. The fixed scroll 121 is fixed to the bearing housing 130 with a bolt or the like (not illustrated). A groove-shaped second communication passage 132c that causes the first communication passage 121f and the first space S1 to communicate with each other is formed on the outer peripheral surface of the annular portion 131.
An outer peripheral surface of the annular portion 131 is in an interference fit with an inner peripheral surface of the casing body 112. Thus, the bearing housing 130 is fixed to the inner side of the casing body 112.

(2-3-2) Recess 132

The recess 132 is formed at the center on an upper surface side of the bearing housing 130. A peripheral wall surface of the recess 132 is constituted by an inner peripheral surface of the annular portion 131. The recess 132 accommodates the orbital scroll 122 in a rotatable state.

(2-3-3) First bearing 133

The first bearing 133 protrudes downward from the center on a lower surface side of the annular portion 131. A first bearing hole 133b penetrating from a bottom of the recess 132 to a lower end of the first bearing 133 is formed in the center of the bearing housing 130. A bearing metal 133a is inserted through an inner peripheral surface of the first bearing hole 133b. The crankshaft 150 is inserted through the bearing metal 133a. Thus, the first bearing 133 rotatably supports the crankshaft 150.

(2-3-4) First oil return oil path 132a and second oil return oil path 132b

The first oil return oil path 132a and the second oil return oil path 132b are oil paths for returning the lubricating oil accumulated at the recess 132 to the bottom wall 113. The first oil return oil path 132a is an oil path extending in the horizontal direction from the bottom of the recess 132 toward the outer peripheral surface of the annular portion 131. The second oil return oil path 132b is an oil path extending downward from an opening of the first oil return oil path 132a formed on the outer peripheral surface of the annular portion 131. The second oil return oil path 132b is formed on the outer peripheral surface of the annular portion 131.

(2-4) Electric motor 140

The electric motor 140 drives the compression mechanism 120. The electric motor 140 is disposed below the bearing housing 130. Specifically, the electric motor 140 is fixed in the casing 110 so as to be separated from the bearing housing 130 in the axial direction of the casing 110. The electric motor 140 is a brushless DC motor. The electric motor 140 includes a stator 141 fixed to an inner wall of the casing 110 and a rotor 142 rotatably accommodated on an inner side of the stator 141 with a slight gap.

(2-4-1) Stator 141

In the stator 141, a copper wire is wound around teeth. A groove-shaped core cut 141a extending along the up-down direction from an upper end surface to a lower end surface of the stator 141 is formed on an outer peripheral surface of the stator 141. A plurality of core cuts 141a is formed at predetermined intervals in a circumferential direction on the outer peripheral surface of the stator 141.
The stator 141 is provided with a notch 141b in which a depth of the core cut 141a is formed deep over a predetermined length from an upper end downward.

(2-4-2) Rotor 142

The rotor 142 is coupled to the orbital scroll 122 via the crankshaft 150 at a rotation center of the rotor 142.

(2-5) Crankshaft 150

The crankshaft 150 couples the compression mechanism 120 and the electric motor 140. The crankshaft 150 is disposed in the casing 110 to have a rotation center along the up-down direction. The crankshaft 150 includes a main shaft 151, an eccentric shaft 152, and an oil path 153.

(2-5-1) Main shaft 151

The main shaft 151 is a portion rotatably supported by the first bearing 133. An upper end surface of the main shaft 151 is positioned at substantially the same height as a bottom surface of the recess 132 of the bearing housing 130.

(2-5-2) Eccentric shaft 152

The eccentric shaft 152 is a portion fitted into the second bearing 123. The eccentric shaft 152 is a portion extending upward from the upper end surface of the main shaft 151. An axial center of the eccentric shaft 152 is located away from a shaft center of main shaft 151. In other words, the shaft center of the eccentric shaft 152 is formed eccentrically to the axial center of main shaft 151.

(2-5-3) Oil path 153

The oil path 153 is formed inside the crankshaft 150. The oil path 153 includes a first oil path 153a, a second oil path 153b, and a third oil path 153c.
The first oil path 153a is an oil path formed along an axial center from a lower end to an upper end of the crankshaft 150.
The second oil path 153b is an oil path formed along an axial radial direction, and causes the first oil path 153a and the outer peripheral surface of the crankshaft 150 to communicate with each other. The second oil path 153b is formed at a position where an opening on an outer peripheral surface side of the crankshaft 150 faces an inner peripheral surface of the first bearing 133.
The third oil path 153c has a D-cut shape formed on an outer peripheral surface of the eccentric shaft 152.
The lower end of the crankshaft 150 is connected to a pumping mechanism 154. The pumping mechanism 154 pumps up the lubricating oil accumulated at the bottom wall 113 by a positive displacement pump action and supplies the lubricating oil to the first oil path 153a.

(2-6) Fluid guide assembly 160

The fluid guide assembly 160 includes a support 161, an oil return guide 162, and a gas guide 163. FIG. 7 is a perspective view of the fluid guide assembly 160. FIG. 8 is a perspective view of the support 161. FIGS. 9A and 9B are perspective views of the oil return guide 162. FIGS. 10A and 10B are perspective views of the gas guide 163. FIGS. 9B and 10B are diagrams when viewed from a position where a surface in contact with the support 161 is visible in a state where each guide is fixed to the support 161. On the contrary, FIGS. 9A and 10A are diagrams when viewed from a position where a surface not in contact with the support 161 is visible in a state where each guide is fixed to the support 161. The oil return guide 162 and the gas guide 163 are examples of a fluid guide.

(2-6-1) Support 161

The support 161 is disposed in the first space S1 located between the bearing housing 130 and the electric motor 140. The support 161 supports the oil return guide 162 and the gas guide 163 in the first space S1. The support 161 is fixed to the casing 110 by welding. The support 161 is fixed to the bearing housing 130 with the bolt 164. The support 161 supports the bearing housing 130 from below. The support 161 includes a body 161a and a stay 161b.
The body 161a is a substantially cylindrical member molded with a metal plate (sheet metal). An outer peripheral surface of the support 161 is formed along the inner peripheral surface of the casing body 112. An outer peripheral surface of the body 161a is fixed to the inner peripheral surface of the casing body 112 by welding. Specifically, the outer peripheral surface of the body 161a is fixed to the inner peripheral surface of the casing body 112 by plug welding. A position of the plug welding is indicated by W in FIG. 3. Accordingly, the support 161 is fixed to the casing 110.
A position at which the support 161 is welded to the casing body 112 is closer to the electric motor 140 than a position (the outer peripheral surface of the annular portion 131) at which the bearing housing 130 is in an interference fit with the casing body 112. In other words, the support 161 is welded to the casing body 112 below the annular portion 131 of the bearing housing 130.
A plate thickness of a portion of the support 161 welded to the casing body 112 is thinner than the plate thickness of the corresponding portion of the casing body 112. Specifically, a plate thickness T2 of the body 161a is thinner than the plate thickness T1 of the casing body 112 (see FIG. 3). The plate thickness T2 of the body 161a is, for example, 4 mm or more and 7 mm or less.
The support 161 supports the bearing housing 130 via the stay 161b. The stay 161b is fixed to the bearing housing 130 with the bolt 164. The stay 161b is formed so as to extend in the horizontal direction from an inner peripheral surface of the body 161a. The stay 161b is provided on the inner peripheral surface of the body 161a so as to extend along a surface of the annular portion 131 included in the bearing housing 130 facing the first space S1 in a state where the support 161 is fixed to the casing body 112. The number of the stays 161b is not limited to one, and may be two or more, for example.
As illustrated in FIG. 8, the body 161a of the support 161 has four slits 161aa, 161ab, 161ac, and 161ad. All of the slits 161aa, 161ab, 161ac, and 161ad are formed upward from a lower end of the support 161.
The slit 161aa is a slit through which the lubricating oil passes. The slit 161aa is formed at a position where the oil return guide 162 is attached. The slit 161ab is a slit through which the refrigerant passes. The slit 161ab is formed at a position where the gas guide 163 is attached.
The slit 161ac is formed at a position corresponding to the discharge pipe 190. The slit 161ad is formed at a position corresponding to a terminal 170 for supplying electric power or the like to the electric motor 140.
The body 161a is provided with a cylindrical portion 161ae in which the slits 161aa, 161ab, 161ac, and 161ad are not formed in a predetermined width downward from an upper end. An outer peripheral surface of the cylindrical portion 161ae faces the inner peripheral surface of the casing body 112 in a state where the support 161 is fixed to the casing body 112.
The support 161 includes a material having better weldability than the bearing housing 130. Although not limited, the material of the bearing housing 130 is, for example, cast iron, and the material of the support 161 is, for example, SPHC (JIS G 3131).

(2-6-2) Oil return guide 162

The oil return guide 162 is disposed in the first space S1 located between the compression mechanism 120 and the electric motor 140, and guides the lubricating oil, which is a fluid flowing into the first space S1, to an outer periphery of the electric motor 140. Specifically, the oil return guide 162 causes a part of the lubricating oil flowing out from a lower end of the second oil return oil path 132b of the bearing housing 130 and flowing into the first space S1 to flow into the core cut 141a of the stator 141. The oil return guide 162 is fixed to an inner peripheral surface of the support 161 by spot welding. The oil return guide 162 is molded with a metal plate or the like. The oil return guide 162 includes a passage portion 162a and a welded portion 162b.
The passage portion 162a serves as a passage for the lubricating oil in a state where the oil return guide 162 is fixed to the support 161. The passage portion 162a is a passage protruding from the inner peripheral surface of the support 161 toward an axial center of the support 161 and having a U-shaped cross section.
The passage portion 162a includes a contraction portion 162aa in which a passage area decreases from the upper side toward the lower side. The contraction portion 162aa is formed such that a height projecting from the inner peripheral surface of the support 161 toward the axial center of the support 161 and a width in the circumferential direction decrease from the upper side toward the lower side.
As illustrated in FIGS. 5 and 8, the slit 161aa of the support 161 is formed at a position facing a part of the contraction portion 162aa and a portion of the passage portion 162a below the contraction portion 162aa in the axial radial direction. The passage portion 162a may be formed such that a part of the contraction portion 162aa and a portion below the contraction portion 162aa are located in the slit 161aa. As illustrated in FIG. 5, a distal end of a portion of the passage portion 162a below the contraction portion 162aa may be inserted into the notch 141b of the stator 141.
The welded portion 162b is fixed to the inner peripheral surface of the support 161 by welding. The welded portion 162b extends from an end edge of the passage portion 162a along the inner peripheral surface of the support 161.
The welded portion 162b is welded to the inner peripheral surface of the support 161,and then, a space surrounded by the passage portion 162a and the inner peripheral surface of the support 161 serves as a lubricating oil passage P1 connecting an opening opened upward and the slit 161aa.

(2-6-3) Gas guide 163

The gas guide 163 is disposed in the first space S1 located between the compression mechanism 120 and the electric motor 140. The gas guide 163 guides a part of the refrigerant that is the fluid flowing into the first space S1 so as to turn along the circumferential direction of the support 161, and guides the remaining refrigerant to the outer periphery of the electric motor 140. Specifically, the gas guide 163 causes a part of the refrigerant flowing out of the lower end of the second communication passage 132c of the bearing housing 130 and flowing in to flow out along the inner peripheral surface of the support 161, and causes the remaining refrigerant to flow into the core cut 141a of the stator 141. The gas guide 163 is fixed to the inner peripheral surface of the support 161 by spot welding. The gas guide 163 is molded with a metal plate or the like. The gas guide 163 includes a first passage portion 163a, a second passage portion 163b, and a welded portion 163c.
The first passage portion 163a and the second passage portion 163b serve as passages for the refrigerant in a state where the gas guide 163 is fixed to the support 161. The first passage portion 163a and the second passage portion 163b are passages protruding from the inner peripheral surface of the support 161 toward the axial center of the support 161 and having a U-shaped cross section.
The first passage portion 163a guides the refrigerant flowing in the up-down direction so as to flow out in the circumferential direction. The first passage portion 163a has an inflow port toward the lower end of the second communication passage 132c, an outflow port toward the circumferential direction on the inner peripheral surface of the support 161, and a curved portion that changes the flow of the refrigerant from the up-down direction to the circumferential direction.
The second passage portion 163b guides the refrigerant flowing in to flow out along the up-down direction. The second passage portion 163b has an inflow port connected to the curved portion of the first passage portion 163a and an outflow port downward below the inflow port.
A connecting portion of the second passage portion 163b to the first passage portion 163a includes a contraction portion 163ba in which a passage area decreases from the upper side to the lower side. The contraction portion 163ba is formed such that a height projecting from the inner peripheral surface of the support 161 toward the axial center of the support 161 and a width in the circumferential direction decrease from the upper side toward the lower side.
As illustrated in FIGS. 6 and 8, the slit 161ab of the support 161 is formed at a position facing a part of the contraction portion 163ba and a portion of the second passage portion 163b below the contraction portion 163ba in the axial radial direction. The second passage portion 163b may be formed such that a part of the contraction portion 163ba and a portion below the contraction portion 163ba are located in the slit 161aa. A distal end of a portion of the second passage portion 163b below the contraction portion 163ba may be inserted into the notch 141b of the stator 141.
The welded portion 163c is fixed to the inner peripheral surface of the support 161 by welding. The welded portion 163c extends from end edges of the first passage portion 163a and the second passage portion 163b along the inner peripheral surface of the support 161.
The welded portion 163c is welded to the inner peripheral surface of the support 161, and then, a space surrounded by the first passage portion 163a and the inner peripheral surface of the support 161 serves as a refrigerant passage P2. The welded portion 163c is welded to the inner peripheral surface of the support 161, and then, a space surrounded by the second passage portion 163b and the inner peripheral surface of the support 161 serves as a refrigerant passage P3 connecting the inflow port connected to the curved portion of the first passage portion 163a and the slit 161ab.

(2-7) Suction pipe 180

The suction pipe 180 guides the sucked refrigerant to the compression mechanism 120. The suction pipe 180 is fixed to the casing 110 such that one end is inserted into the suction hole 121d of the compression mechanism 120 and the other end is located outside the casing 110.

(2-8) Discharge pipe 190

The discharge pipe 190 guides the compressed refrigerant to the outside of the casing 110. The discharge pipe 190 is fixed to the casing 110 such that one end is located in the first space S1 (not illustrated) and the other end is located outside the casing 110.

(3) Operation of compressor 100

(3-1) Flow of refrigerant in compressor 100

The flow of the refrigerant in the compressor 100 will be described. When the electric motor 140 is activated, the crankshaft 150 starts an axial rotational movement with a rotation of the rotor 142. An axial rotational force of the crankshaft 150 is transmitted to the orbital scroll 122 via the second bearing 123. The orbiting scroll 122, which is restricted from rotating by the Oldham's coupling, revolves orbitally without rotating about an axial rotation center of the crankshaft 150. On the other hand, the refrigerant (gas refrigerant) flows into the compression chamber 124 of the compression mechanism 120 via the suction pipe 180. An orbital motion of the orbital scroll 122 causes the compression chamber 124 to move from an outer peripheral portion toward a central portion of the fixed scroll 121 while gradually decreasing the volume of the compression chamber 124. As a result, the refrigerant in the compression chamber 124 is compressed and discharged from the discharge hole 121e to the second space S2. The discharged refrigerant flows into the gas guide 163 via the first communication passage 121f and the second communication passage 132c. A part of the refrigerant flowing into the gas guide 163 flows into the refrigerant passage P2, and the remaining refrigerant flows into the refrigerant passage P3. The refrigerant flowing into the refrigerant passage P2 is guided by the first passage portion 163a and then flows out along the circumferential direction. The refrigerant flowing into the refrigerant passage P3 is guided by the second passage portion 163b, passes through the slit 161aa, and flows into the core cut 141a. The refrigerant flowing into the core cut 141a passes through a space surrounded by the core cut 141a and the inner peripheral surface of the casing body 112, and then, the refrigerant is finally discharged from the discharge pipe 190 through the bottom wall 113. The refrigerant flowing into the refrigerant passage P3 flows along the circumferential direction on the inner peripheral surface of the support 161. At this time, a centrifugal force generated by the flow in the circumferential direction separates the mixed lubricating oil from the refrigerant.
The refrigerant discharged from the compressor 100 circulates in the refrigerant circuit 6, and then is sucked again from the suction pipe 180 into the compressor 100 to repeat the refrigeration cycle.

(3-2) Flow of lubricating oil in compressor 100

The flow of the lubricating oil in the compressor 100 will be described.
When the electric motor 140 is activated and the crankshaft 150 starts the axial rotational movement, the lubricating oil accumulated at the bottom wall 113 is sucked into the first oil path 153a of the crankshaft 150 by the positive displacement pump action of the pumping mechanism 154. A part of the lubricating oil sucked into the first oil path 153a is supplied to the inner peripheral surface of the first bearing 133 through the second oil path 153b. The remaining part of the lubricating oil sucked into the first oil path 153a flows out from an upper end of the first oil path 153a, is supplied to an inner peripheral surface of the second bearing 123 through the third oil path 153c, and is supplied to a slider between the fixed scroll 121 and the orbital scroll 122 through a flow path (not illustrated).
The lubricating oil supplied to the inner peripheral surface of the second bearing 123 lubricates a portion between the inner peripheral surface of the second bearing 123 and the outer peripheral surface of the eccentric shaft 152, then passes through the bottom of the recess 132 of the bearing housing 130, and flows into the first oil return oil path 132a. The lubricating oil flowing into the first oil return oil path 132a passes through the second oil return oil path 132b and flows into the lubricating oil passage P1 surrounded by the oil return guide 162 and the inner peripheral surface of the support 161. The lubricating oil flowing into the lubricating oil passage P1 is guided by the oil return guide 162, passes through the slit 161ab, and flows into the core cut 141a. The lubricating oil flowing into the core cut 141a passes through a space surrounded by the core cut 141a and the inner peripheral surface of the casing body 112, and returns to the bottom wall 113.

(4) Characteristics

(4-1)
The compressor 100 includes the casing 110, the bearing housing 130, the electric motor 140, and the support 161. The casing 110 has a tubular shape. The bearing housing 130 and the electric motor 140 are fixed in the casing 110 so as to be separated from each other in the axial direction of the casing 110. The support 161 is disposed in the first space S1 located between the bearing housing 130 and the electric motor 140. The bearing housing 130 is fixed to the casing 110 by interference fitting. The support 161 is fixed to the casing 110 by welding and supports the bearing housing 130.
The bearing housing of the compressor is fixed to the casing by interference fitting, and is supported by the support fixed to the casing by welding. Therefore, in the compressor, the bearing housing can be suitably fixed to the casing without using the welding pin.
(4-2)
The support 161 is fixed to the bearing housing 130 with the bolt 164.
In the compressor 100, with the bolt, the support is easily fixed to the bearing housing.
(4-3)
The support 161 includes the stay 161b extending along the surface of the bearing housing 130 facing the first space S1. The stay 161b is fixed to the bearing housing 130 with a bolt 164.
(4-4)
The support 161 includes the cylindrical portion 161ae whose outer peripheral surface faces an inner peripheral surface of the casing 110.
The support 161, which has the cylindrical portion 161ae, can be easily assembled to the casing body 112 by inserting the outer peripheral surface of the cylindrical portion 161ae while facing the inner peripheral surface of the casing body 112. Therefore, in the compressor 100, the support 161 is easily assembled to the casing.
(4-5)
The compressor 100 further includes the oil return guide 162 and the gas guide 163 that are disposed in the first space S1 and guide the fluid flowing between the bearing housing 130 and the electric motor 140 to the outer periphery of the electric motor 140. The oil return guide 162 and the gas guide 163 are fixed to the support by spot welding.
Since the fluid guide guides the refrigerant and the lubricating oil discharged from the compression mechanism, the compressor prevents a lubricating oil included in the refrigerant from scattering due to the rotation of the rotor of the electric motor.
(4-6)
A position at which the support 161 is welded to the casing 110 is closer to the electric motor 140 than a position at which the bearing housing 130 is in an interference fit with the casing.
In the compressor, a load generated in the compression mechanism along with operation can be received by the bearing housing and the support. Therefore, the compressor can reduce a moment acting on a position at which the bearing housing is fixed to (in an interference fit with) the casing during operation.
(4-7)
The plate thickness T2 of a portion of the support 161 welded to the casing 110 is thinner than the plate thickness T1 of the corresponding portion of the casing 110.
(4-8)
The support 161 is fixed to the casing 110 by plug welding.
(4-9)
The support 161 includes a material having better weldability than the bearing housing 130.
The support is firmly fixed to the bearing housing by welding.
(4-10)
The compressor 100 compresses a carbon dioxide refrigerant.
In a case where carbon dioxide having a high pressure at room temperature is used as the refrigerant, the casing of the compressor is formed to have a plate thickness thicker than a plate thickness of a compressor used for another refrigerant in order to secure pressure resistance. In this case, since it is necessary to increase an amount of heat input, the welding pin greatly expands at a time of welding, a distal end of a tooth shape formed on an outer periphery is plastically deformed, a press-fit holding force is reduced, and the bearing housing cannot be suitably fixed to the casing in some cases.
The bearing housing of the compressor is fixed to the casing by interference fitting, and is supported by the support fixed to the casing by welding. Therefore, in the compressor, even in a case where the carbon dioxide refrigerant is compressed, the bearing housing can be suitably fixed to the casing without using the welding pin.
(4-11)
The refrigeration cycle apparatus 1 includes the compressor 100.

(5) Modifications

(5-1) Modification A

The support 161 may be fixed to the bearing housing 130 by press fitting. Specifically, the support 161 may be fixed to the bearing housing 130 by press-fitting the inner peripheral surface of the support 161 into an outer peripheral surface of the bearing housing 130. In this case, the support 161 is not required to include the stay 161b.
In the compressor 100 according to Modification A, by press fitting, the support 161 is firmly fixed to the bearing housing 130.

(5-2) Modification B

The body 161a of the support 161 is not required to have a cylindrical shape. Specifically, the body 161a may include a metal plate obtained by circumferentially dividing a cylinder whose outer peripheral surface is formed along the inner peripheral surface of the casing body 112.

While the embodiment of the present disclosure has been described above, it will be understood that various changes in forms and details can be made without departing from the gist and scope of the present disclosure recited in the claims.

REFERENCE SIGNS LIST

1: refrigeration cycle apparatus
100: compressor
110: casing
120: compression mechanism
130: bearing housing
140: electric motor
161: support
161b: stay
162: oil return guide (fluid guide)
163: gas guide (fluid guide)
164: bolt
S1: first space

CITATION LIST

PATENT LITERATURE

Patent Literature 1: JP H6-66267 A

Claims

A compressor (100) comprising:
a casing (110) having a tubular shape;

a bearing housing (130) and an electric motor (140) that are fixed in the casing (110) so as to be separated from each other in an axial direction of the casing (110); and

a support (161) disposed in a first space (S1) located between the bearing housing (130) and the electric motor (140),

wherein the bearing housing (130) is fixed to the casing (110) by interference fitting, and

the support (161) is fixed to the casing (110) by welding and supports the bearing housing (130).
The compressor (100) according to claim 1, wherein the support (161) is fixed to the bearing housing (130) with a bolt (164).
The compressor (100) according to claim 2, wherein
the support (161) includes a stay (161b) extending along a surface of the bearing housing (130) facing the first space (S1), and

the stay (161b) is fixed to the bearing housing (130) with the bolt (164).
The compressor (100) according to claim 1, wherein the support (161) is fixed to the bearing housing (130) by press fitting.
The compressor (100) according to any one of claims 1 to 4, wherein the support (161) includes a cylindrical portion (161ae) whose outer peripheral surface facing an inner peripheral surface of the casing (110).
The compressor (100) according to any one of claims 1 to 5, further comprising a fluid guide (162, 163) that is disposed in the first space (S1) and guides a fluid flowing between the bearing housing (130) and the electric motor (140) to an outer periphery of the electric motor (140),
wherein the fluid guide (162, 163) is fixed to the support (161) by spot welding.
The compressor (100) according to any one of claims 1 to 6, wherein a position at which the support (161) is welded to the casing (110) is closer to the electric motor (140) than a position at which the bearing housing (130) is in an interference fit with the casing (110).
The compressor (100) according to any one of claims 1 to 7, wherein the support (161) has a plate thickness (T2) of a portion welded to the casing (110), the plate thickness (T2) being thinner than a plate thickness (T1) of a corresponding portion of the casing (110).
The compressor (100) according to any one of claims 1 to 8, wherein the support (161) is fixed to the casing (110) by plug welding.
The compressor (100) according to any one of claims 1 to 9, wherein the support (161) includes a material having better weldability than the bearing housing (130).
The compressor (100) according to any one of claims 1 to 10, compressing a carbon dioxide refrigerant.
The compressor (100) according to any of the preceding claims, wherein the support (161) includes a body (161a) and a stay (161b), the body (161a) being a substantially cylindrical member molded with a metal plate, and wherein an outer peripheral surface of the support (161) is formed along the inner peripheral surface of a casing body (112).
The compressor (100) according to claim 12, wherein an outer peripheral surface of the body (161a) is fixed to the inner peripheral surface of the casing body (112) by welding.
The compressor (100) according claim 13, wherein a position at which the support (161) is welded to the casing body (112) is closer to the electric motor (140) than to a position at which the bearing housing (130) is in an interference fit with the casing body (112).
A refrigeration cycle apparatus (1) comprising the compressor (100) according to any one of the preceding claims.