WO2017069122A1 - Centrifugal compressor - Google Patents

Abstract

This centrifugal compressor is provided with a rotating shaft, an electric motor having a rotor, a cylindrical boss through which the rotating shaft is inserted, and a radial bearing. The rotor has a rotor end surface, which is the end surface of the rotating shaft in the axial direction. The boss has a boss end surface, which is the end surface of the rotating shaft in the axial direction. The rotor end surface and the boss end surface face each other in the axial direction of the rotating shaft. A thrust bearing for bearing thrust force generated by rotation of an impeller is provided between the rotor end surface and the boss end surface.

Description

Centrifugal compressor

The present invention relates to a centrifugal compressor.

The centrifugal compressor includes, for example, a rotating shaft, an electric motor that rotates the rotating shaft, an impeller that compresses fluid by rotating with the rotation of the rotating shaft, a housing that houses the rotating shaft, the electric motor, and the impeller. It has. For example, see Patent Document 1. Patent Document 1 describes that a centrifugal compressor has a flange portion as a thrust liner that rotates integrally with a rotary shaft, and two thrust bearings that sandwich the flange portion.

JP 2009-257165 A

Here, since the thrust liner rotates when the rotating shaft rotates, wind loss occurs in the thrust liner. For this reason, there is concern about a decrease in the efficiency of the centrifugal compressor.
An object of the present invention is to provide a centrifugal compressor capable of improving efficiency.

A centrifugal compressor that achieves the above object has a rotating shaft, a rotor attached to the rotating shaft, an electric motor that rotates the rotating shaft, and fluid by rotating along with the rotation of the rotating shaft. An impeller to be compressed, a housing in which the rotating shaft, the electric motor, and the impeller are housed, a cylindrical boss provided in the housing and through which the rotating shaft is inserted, the boss, and the rotating shaft And a radial bearing that rotatably supports the rotating shaft. The rotor has a rotor end surface that is an end surface in the axial direction of the rotating shaft. The boss has a boss end surface which is an end surface in the axial direction of the rotating shaft. The rotor end surface and the boss end surface are opposed to each other in the axial direction of the rotation shaft. The centrifugal compressor includes a thrust bearing that receives a thrust force generated by the rotation of the impeller between the rotor end surface and the boss end surface.

Sectional drawing which shows the outline | summary of a centrifugal compressor and a vehicle air conditioner. Sectional drawing which expands and shows a rotor and a thrust bearing. Sectional drawing which shows the outline | summary of the vehicle air conditioner of another example.

Hereinafter, an embodiment of a centrifugal compressor will be described with reference to the drawings. In the present embodiment, the centrifugal compressor is mounted on the vehicle. 1 to 3, the rotating shaft 12 is shown in a side view for convenience of illustration. For convenience of illustration, the thicknesses of the electromagnetic steel plate 51, the clamping plates 52 and 53, the spacers 55 and 56, and the thrust bearings 91 and 92 are shown different from the actual dimensions.

As shown in FIG. 1, the centrifugal compressor 10 includes a housing 11 that constitutes an outline thereof. The housing 11 has, for example, a cylindrical shape as a whole. The housing 11 is made of a material having heat conductivity such as metal.

The centrifugal compressor 10 includes a rotating shaft 12, an electric motor 13 that rotates the rotating shaft 12, and first and second impellers 14 and 15 that are attached to the rotating shaft 12, which are housed in a housing 11. ing. The rotating shaft 12 has a main body 12a and a tip 12b having a diameter smaller than that of the main body 12a and having the first and second impellers 14 and 15 attached thereto.

The housing 11 includes a front housing 20 that partitions the first and second impeller chambers A1 and A2 that house the first and second impellers 14 and 15, respectively. The front housing 20 is composed of three parts 21 to 23. Each part 21 to 23 is a state in which the intermediate part 23 is sandwiched between the first part 21 and the second part 22 from the axial direction Z of the rotary shaft 12. It is unitized.

The first part 21 has a substantially cylindrical shape having a first compressor through-hole 21a penetrating in the axial direction Z of the rotary shaft 12. The first part 21 has first and second end faces 21 b and 21 c that are positioned on opposite sides in the axial direction Z of the rotary shaft 12. The first compressor through hole 21a is open to the first and second end faces 21b, 21c of the first part 21. The first end surface 21 b of the first part 21 is in contact with the intermediate part 23. The first compressor through hole 21a has a truncated cone shape with a gradually reduced diameter from the opening of the first end face 21b to the midway position in the axial direction Z of the rotary shaft 12. The first compressor through hole 21a has a columnar shape with the same diameter from the midway position to the opening of the second end face 21c.

The second part 22 has a substantially cylindrical shape with the axial direction Z of the rotary shaft 12 as the axial direction. The second part 22 has first and second end surfaces 22 a and 22 b that are located on opposite sides in the axial direction Z of the rotary shaft 12. The first end surface 22 a of the second part 22 is in contact with the intermediate part 23. A recess 22c is formed in the second end surface 22b. A second compressor through hole 22d penetrating in the axial direction Z of the rotary shaft 12 is formed on the bottom surface of the recess 22c. The second compressor through-hole 22d has a truncated cone shape with a gradually reduced diameter from the opening facing the intermediate part 23 to the middle position in the axial direction Z of the rotary shaft 12, and from the middle position, the intermediate part 23 has the above-mentioned shape. Up to the opening opposite to the opening, it has a cylindrical shape with the same diameter.

The intermediate part 23 has a substantially disk shape with the axial direction Z of the rotary shaft 12 as the plate thickness direction. The intermediate part 23 is a first intermediate part end surface 23a that is in contact with the first end surface 21b of the first part 21, and an end surface opposite to the first intermediate part end surface 23a. The second intermediate part end surface 23b is in contact with the end surface 22a. The first impeller chamber A1 is partitioned by the inner surface of the first compressor through hole 21a and the first intermediate part end surface 23a, and the second impeller chamber A2 is formed by the inner surface of the second compressor through hole 22d and the second intermediate part end surface. 23b. That is, the intermediate part 23 partitions the first impeller chamber A1 and the second impeller chamber A2.

The intermediate part 23 has an intermediate part through hole 23c through which the rotary shaft 12 is inserted. The distal end portion 12b of the rotating shaft 12 is disposed in a state of penetrating the intermediate part through hole 23c, and is disposed across both the impeller chambers A1 and A2. The first impeller 14 is attached to a portion of the distal end portion 12b of the rotating shaft 12 that is disposed in the first impeller chamber A1, and the second impeller 15 is a second portion of the distal end portion 12b of the rotating shaft 12. It is attached to the part arrange | positioned in impeller chamber A2.

The first impeller 14 has a substantially truncated cone shape with a diameter gradually reduced from the base end surface 14a toward the front end surface 14b, and is disposed in the first impeller chamber A1 along the inner surface of the first compressor through hole 21a. ing. Similarly, the second impeller 15 has a substantially frustoconical shape with a diameter gradually reduced from the base end surface 15a toward the front end surface 15b, and is arranged in the second impeller chamber A2 along the inner surface of the second compressor through hole 22d. Is arranged. The base end surfaces 14a and 15a of both the impellers 14 and 15 are opposed to each other.

The front housing 20 (specifically, the first part 21) has a first suction port 30 through which fluid is sucked. The first suction port 30 opens on the second end surface 21c of the first compressor through hole 21a. That is, the first compressor through hole 21a constitutes the first suction port 30 and the first impeller chamber A1. The fluid sucked from the first suction port 30 flows into the first impeller chamber A1.

As shown in FIG. 1, the front housing 20 includes a first diffuser channel 31 disposed on the radially outer side of the rotary shaft 12 with respect to the first impeller chamber A1, and a first diffuser channel 31 through the first diffuser channel 31. A first discharge chamber 32 communicating with the 1 impeller chamber A1 is defined. The first diffuser flow path 31 has an annular shape surrounding the first impeller 14. The first discharge chamber 32 is disposed on the radially outer side of the rotary shaft 12 with respect to the first diffuser flow path 31 and communicates with a first discharge port 33 formed in the front housing 20.

Similarly, the front housing 20 includes a second diffuser passage 34 disposed radially outside the rotation shaft 12 with respect to the second impeller chamber A2, and the second impeller chamber A2 via the second diffuser passage 34. A second discharge chamber 35 communicating with the second discharge chamber 35 is partitioned. The fluid in the second discharge chamber 35 is discharged from a second discharge port 36 formed in the front housing 20.

As shown in FIG. 1, the housing 11 includes a motor housing 41 and an end plate 42 that define a motor chamber A <b> 3 that houses the electric motor 13.
The motor housing 41 has, for example, a bottomed cylinder shape having a bottom 41a and opened on the opposite side to the bottom 41a. The axial direction of the motor housing 41 coincides with the axial direction Z of the rotary shaft 12. The end plate 42 has a disk shape having the same diameter as the outer diameter of the motor housing 41, and the thickness direction of the end plate 42 coincides with the axial direction Z of the rotary shaft 12. The motor housing 41 and the end plate 42 are assembled in a state where the open end of the motor housing 41 abuts against the first plate surface 42 a of the end plate 42. The opening of the motor housing 41 is closed by the end plate 42. The motor chamber A3 is partitioned by a motor housing 41 and an end plate 42.

The bottom 41a of the motor housing 41 is formed with a bottom communication hole 41b through which the rotary shaft 12 is inserted and for communication between the motor chamber A3 and the second impeller chamber A2. The bottom communication hole 41 b is formed across both the portion of the bottom 41 a of the motor housing 41 that overlaps the main body 12 a as viewed from the axial direction Z of the rotating shaft 12 and the surrounding portion thereof. When viewed from the axial direction Z, the second part 22 overlaps the recess 22c. The motor chamber A3 and the second impeller chamber A2 communicate with each other via the bottom communication hole 41b and the recess 22c of the second part 22. The bottom communication holes 41b are not formed over the entire circumference of the rotating shaft 12, but are provided in a state of being arranged in the circumferential direction of the rotating shaft 12 at a predetermined interval.

As shown in FIG. 2, the electric motor 13 includes a rotor 50 attached to the rotary shaft 12 (specifically, the main body 12a of the rotary shaft 12). The rotor 50 as a whole has a cylindrical shape (specifically, a cylindrical shape) in which the axial direction Z of the rotary shaft 12 is the axial direction. The rotor 50 has first and second rotor end faces 50a and 50b located on opposite sides in the axial direction Z of the rotary shaft 12. The rotor 50 includes a plurality of electromagnetic steel plates 51 stacked in the axial direction Z of the rotary shaft 12, and first and second clamping plates 52 and 53 that clamp the plurality of electromagnetic steel plates 51 from the axial direction Z of the rotary shaft 12. I have. The first and second clamping plates 52 and 53 make a pair. In the present embodiment, the electromagnetic steel plate 51 and the first and second sandwiching plates 52 and 53 have the same shape, and are specifically annular when viewed from the axial direction Z of the rotary shaft 12. For convenience of explanation, in the following explanation, the side approaching the electromagnetic steel sheet 51 in the axial direction Z of the rotating shaft 12 is referred to as the inner side, and the side away from the electromagnetic steel sheet 51 is referred to as the outer side.

The rotor 50 includes a plurality of electromagnetic steel plates 51 and rivets 54 as connecting members that connect the first and second clamping plates 52 and 53. The rivet 54 includes a barrel portion 54a inserted through the plurality of electromagnetic steel plates 51 and the first and second clamping plates 52 and 53, a first head portion 54b provided at both ends in the axial direction Z of the barrel portion 54a, and And a second head 54c. One of the first and second heads 54b and 54c is formed in advance before caulking, and the other is formed by crushing the tip of the body portion 54a by caulking.

The plurality of electromagnetic steel plates 51 and the first and second clamping plates 52 and 53 are connected by being sandwiched between the first and second heads 54b and 54c. Specifically, the plurality of electromagnetic steel plates 51 and the first and second clamping plates 52, 53 are formed with through holes 51 a, 52 a, 53 a that communicate with the axial direction Z of the rotary shaft 12. These through holes 51 a, 52 a, 53 a have the same shape and communicate with each other in the axial direction Z of the rotary shaft 12. The trunk portion 54a is inserted through each of the through holes 51a, 52a, and 53a. The first and second heads 54b and 54c are larger in diameter than the through holes 51a, 52a and 53a. The first and second heads 54b, 54c are hooked on the sandwiching outer surfaces 52c, 53c opposite to the sandwiching inner surfaces 52b, 53b in contact with the electromagnetic steel plate 51 in the sandwiching plates 52, 53. Thereby, the some electromagnetic steel plate 51 and the 1st and 2nd clamping plates 52 and 53 are unitized. The first and second clamping plates 52 and 53 are fixed to the rotary shaft 12 so as to rotate integrally with the rotary shaft 12. For this reason, as the rotating shaft 12 rotates, the plurality of electromagnetic steel plates 51 and the first and second sandwiching plates 52 and 53 rotate together. In this case, the first and second heads 54b and 54c protrude from the first and second sandwiching outer surfaces 52c and 53c.

As shown in FIG. 1, in the present embodiment, a plurality of rivets 54 are attached while being spaced apart from each other in the circumferential direction of the rotating shaft 12. The first sandwiching outer surface 52c corresponds to the “plate surface of the first sandwiching plate”, and the second sandwiching outer surface 53c corresponds to the “plate surface of the second sandwiching plate”.

As shown in FIG. 2, the rotor 50 includes first and second spacers 55 and 56 provided outside the first and second clamping plates 52 and 53 in the axial direction Z of the rotary shaft 12. The first and second spacers 55 and 56 have, for example, a disk shape in which the axial direction Z of the rotary shaft 12 is the plate thickness direction. The diameters of the first and second spacers 55 and 56 are the electromagnetic steel plate 51 and the first And the same as the second clamping plates 52 and 53. The plate thickness of the first and second spacers 55 and 56 is formed thicker than the first and second heads 54b and 54c.

The first spacer 55 has a first contact surface 55a that contacts the first sandwiching outer surface 52c, and the surface of the first spacer 55 that is disposed on the opposite side of the first contact surface 55a is the first. The rotor end surface 50a is configured.

The second spacer 56 has a second contact surface 56a that contacts the second sandwiching outer surface 53c, and the surface of the second spacer 56 that is disposed on the opposite side of the second contact surface 56a is the second. The rotor end surface 50b is configured.

The first and second spacers 55 and 56 have first and second recesses 55b and 56b as accommodating portions for accommodating the first and second head portions 54b and 54c. The first recess 55b corresponds to the first housing portion, and the second recess 56b corresponds to the second housing portion. The first and second recesses 55b and 56b are recessed from the first and second contact surfaces 55a and 56a toward the outside in the axial direction Z. The depth dimensions of the first and second recesses 55b and 56b are set larger than the thicknesses of the first and second heads 54b and 54c within a range shorter than the plate thickness of the first and second spacers 55 and 56. Has been. Therefore, the first and second rotor end surfaces 50a and 50b are flat surfaces on which no depressions corresponding to the first and second recesses 55b and 56b are formed.

The first and second spacers 55 and 56 include the first and second heads 54b and 54c in the first and second recesses 55b and 56b, and the first and second contact surfaces 55a and 56a, The first and second sandwiching plates 52 and 53 are fixed in a state where the first and second sandwiching outer surfaces 52c and 53c are in contact with each other. The first and second clamping plates 52 and 53 and the first and second spacers 55 and 56 may be fixed in any manner such as adhesion and engagement.

Here, the first rotor end surface 50a is configured to be flatter than the plate surface of the electromagnetic steel plate 51 and the plate surface of the first sandwich plate 52 (specifically, the first sandwich outer surface 52c), and the second rotor end surface 50b. Is configured to be flatter than the plate surface of the electromagnetic steel plate 51 and the plate surface of the second sandwich plate 53 (specifically, the second sandwich outer surface 53c). In other words, the surface roughness (for example, arithmetic average roughness) is lower on the first and second rotor end surfaces 50a and 50b than on the first and second sandwiching outer surfaces 52c and 53c.

A method for manufacturing the rotor 50 of this embodiment will be briefly described. The method for manufacturing the rotor 50 includes a laminating step of laminating a plurality of electromagnetic steel plates 51 and first and second sandwiching plates 52 and 53, and an inserting step of inserting the trunk portion 54a of the rivet 54 into the laminated body. Yes. The rivet 54 in the insertion step is provided with a head only at one end portion of both end portions in the axial direction Z of the body portion 54a.

And the manufacturing method of the rotor 50 is the said lamination | stacking by crushing the front-end | tip part (specifically the edge part on the opposite side to a head among the both ends of the axial direction Z of the trunk | drum 54a) in the rivet 54. A caulking process for connecting the bodies is provided. By the caulking process, a head is formed at the distal end portion of the trunk portion 54a, and first and second head portions 54b and 54c are formed at both end portions in the axial direction Z of the trunk portion 54a.

Thereafter, the method for manufacturing the rotor 50 includes a step of attaching and fixing the first and second spacers 55 and 56 to the first and second holding plates 52 and 53. In this step, the first and second spacers 55 and 56 are arranged so that the first and second heads 54b and 54c are accommodated in the first and second recesses 55b and 56b of the first and second spacers 55 and 56, respectively. Are attached to the first and second clamping plates 52, 53.

As shown in FIG. 1, the electric motor 13 is disposed on the radially outer side of the rotary shaft 12 with respect to the rotor 50 and includes a stator 57 fixed to the motor housing 41. The rotor 50 and the stator 57 are disposed on the same axis as the rotary shaft 12 and face the radial direction of the rotary shaft 12. The stator 57 includes a cylindrical stator core 58 and a coil 59 wound around the stator core 58. When the current flows through the coil 59, the rotor 50 and the rotary shaft 12 rotate integrally.

The motor housing 41 has a second suction port 60 formed therein. The second suction port 60 is disposed at a position closer to the end plate 42 than the electric motor 13 in the motor housing 41. When the fluid flows from the second suction port 60, the motor chamber A3 is filled with the fluid.

The centrifugal compressor 10 includes an inverter 61 as a drive circuit that drives the electric motor 13 and an inverter case (circuit case) 62 that is used to partition an inverter chamber (circuit chamber) A4 that accommodates the inverter 61. Yes. The inverter case 62 has a bottomed cylindrical shape with one end opened, and is attached to the housing 11 from the axial direction Z of the rotary shaft 12. The opening end of the inverter case 62 and the second plate surface 42b of the end plate 42 opposite to the first plate surface 42a are abutted, and the opening of the inverter case 62 is blocked by the end plate 42. Yes. The inverter chamber A4 is partitioned by an inverter case 62 and an end plate 42. The inverter chamber A4 and the motor chamber A3 are partitioned through an end plate 42. In other words, the end plate 42 functions as a partition wall that partitions the motor chamber A3 and the inverter chamber A4.

According to such a configuration, the inverter 61 and the fluid in the motor chamber A3 can exchange heat via the end plate 42. For this reason, the heat generated in the inverter 61 is transmitted through the end plate 42 to the motor chamber A3 and is absorbed by the fluid in the motor chamber A3.

As shown in FIG. 1, first and second bosses 71 and 72 into which a rotary shaft 12 (specifically, a main body 12 a) is inserted are provided in a motor chamber A <b> 3 that is a housing 11. The first and second bosses 71 and 72 make a pair. The first and second bosses 71 and 72 are cylindrical, and more specifically, a cylindrical shape having an inner diameter larger than the outer diameter of the main body 12a of the rotating shaft 12 and an outer diameter that is the same as the outer diameter of the rotor 50. is there. The axial lines of both bosses 71 and 72 coincide with the axial line of the main body 12a. The first and second bosses 71, 72 are arranged so as to face the axial direction Z of the rotary shaft 12 through the rotor 50.

The first boss 71 stands from the first plate surface 42a of the end plate 42 toward the axial direction Z of the rotary shaft 12, specifically toward the first rotor end surface 50a. The tip surface of the first boss 71, specifically, the end surface of the first boss 71 in the axial direction Z of the rotary shaft 12 is defined as the first boss end surface 71a. The first boss end surface 71a and the first rotor end surface 50a are disposed so as to face each other in a state of being separated in the axial direction Z of the rotary shaft 12. A portion of the main body 12 a of the rotating shaft 12 that is opposite to the side on which the tip 12 b is provided is inserted through the first boss 71.

The second boss 72 stands from the bottom 41a of the motor housing 41 toward the axial direction Z of the rotating shaft 12, specifically toward the second rotor end surface 50b. The end surface of the second boss 72, specifically, the end surface of the second boss 72 in the axial direction Z of the rotating shaft 12 is defined as a second boss end surface 72a. The second boss end surface 72a and the second rotor end surface 50b are arranged so as to face each other in a state of being separated in the axial direction Z of the rotating shaft 12. A portion of the main body 12 a of the rotating shaft 12 on the side where the tip 12 b is provided is inserted through the second boss 72.

Incidentally, as already described, the bottom communication holes 41b are provided in a state where a plurality of the bottom communication holes 41b are arranged at a predetermined interval in the circumferential direction of the rotating shaft 12. For this reason, the bottom 41a and the second boss 72 of the motor housing 41 are portions where the bottom communication hole 41b is not formed in a portion overlapping the second boss 72 when viewed from the axial direction Z of the rotating shaft 12 in the bottom 41a. It is integrated through.

The bottom communication hole 41b is formed across both the portion overlapping the second boss 72 and the surrounding portion when viewed from the axial direction Z of the rotating shaft 12. For this reason, the fluid in the motor chamber A <b> 3 flows toward the second impeller chamber A <b> 2 through the opening portion of the bottom communication hole 41 b around the second boss 72.

As shown in FIGS. 1 and 2, between the bosses 71 and 72, specifically, the inner peripheral surfaces 71 b and 72 b of the bosses 71 and 72, and the outer peripheral surface 12 c of the rotary shaft 12 (specifically, the main body 12 a). Are provided with first and second radial bearings 81 and 82 for rotatably supporting the rotary shaft 12.

The first and second radial bearings 81 and 82 are, for example, flexible non-contact type dynamic pressure bearings. For example, the first radial bearing 81 provided between the first boss 71 and the rotary shaft 12 is provided on the radially outer side of the rotary shaft 12 with respect to the outer peripheral surface 12 c of the rotary shaft 12. A radial top foil 83 is sometimes provided to support the rotating shaft 12 in a non-contact state. The radial top foil 83 is configured so that it can be displaced in the radial direction of the rotating shaft 12 but does not rotate with the rotation of the rotating shaft 12. In detail, for example, the radial top foil 83 is not a completely closed annular shape, but is a thin cylindrical tube with a part cut off. The radial top foil 83 includes, as both ends in the circumferential direction, a fixed end fixed to the inner peripheral surface 71b of the first boss 71 and an end opposite to the fixed end, And free ends that are spaced apart in the direction. In this case, while the rotation of the radial top foil 83 is restricted, the radial top foil 83 can be displaced so that a gap is formed between the radial top foil 83 and the outer peripheral surface 12c of the rotating shaft 12 by elastic deformation. Yes.

The first radial bearing 81 includes a radial bump foil 84 that is provided on the radially outer side of the rotary shaft 12 with respect to the radial top foil 83 and elastically supports the radial top foil 83. The radial bump foil 84 includes a plurality of protrusions protruding radially inward of the rotary shaft 12 and surrounds the radial top foil 83 in a state where the plurality of protrusions and the radial top foil 83 are in contact with each other. . The radial bump foil 84 is elastically deformed in a state in which the radial top foil 83 is movable in the radial direction of the rotary shaft 12 by elastically deforming or restoring the original shape so that a plurality of convex portions are crushed. I support it. Incidentally, a radial gap 85 is formed between the radial top foil 83 and the radial bump foil 84. The radial gap 85 is open in the axial direction Z of the rotary shaft 12.

According to this configuration, when the rotating shaft 12 rotates, a non-contact state in which a gap is formed between the radial top foil 83 and the outer peripheral surface 12 c of the rotating shaft 12 due to the dynamic pressure generated by the rotation of the rotating shaft 12. Thus, the rotating shaft 12 is rotatably supported. The same applies to the second radial bearing 82 provided between the second boss 72 and the rotary shaft 12.

As shown in FIGS. 1 and 2, the centrifugal compressor 10 includes first and second thrust bearings 91 and 92 that receive a thrust force generated by the rotation of both the impellers 14 and 15. Both thrust bearings 91 and 92 are provided in the motor chamber A3 on both sides in the axial direction Z of the rotary shaft 12 with respect to the rotor 50. Specifically, the first thrust bearing 91 is provided between the first rotor end surface 50a and the first boss end surface 71a, and the second thrust bearing 92 includes the second rotor end surface 50b, the second boss end surface 72a, and the like. It is provided between.

In the present embodiment, the first and second thrust bearings 91 and 92 are provided with the first and second thrust bearings 91 and 92 and the first and second rotor end faces 50a and 50b by dynamic pressure generated by the rotation of the rotor 50. It is a non-contact type dynamic pressure bearing which receives a thrust force in a non-contact state in which gaps are respectively formed.

The first and second thrust bearings 91 and 92 have the same configuration except that they are symmetrical. For this reason, the first thrust bearing 91 will be described in detail, and a detailed description of the second thrust bearing 92 will be omitted.

The first thrust bearing 91 is generally annular (specifically, annular). The first thrust bearing 91 has a thrust top foil 93 and a thrust bump foil 94. The thrust top foil 93 is disposed between the first boss end surface 71a and the first rotor end surface 50a at a position closer to the first rotor end surface 50a than to the first boss end surface 71a. The thrust bump foil 94 is disposed between the first rotor end surface 50a and the first boss end surface 71a at a position closer to the first boss end surface 71a than to the first rotor end surface 50a.

The thrust top foil 93 is configured by, for example, a plurality of fan-shaped and thin plate-shaped top foil parts arranged in parallel in the circumferential direction of the rotating shaft 12, and has an annular shape (in detail, an annular shape) as a whole. . The thrust top foil 93 is configured to be able to be displaced in the axial direction Z of the rotating shaft 12, but not to rotate with the rotation of the rotating shaft 12. For example, one end of each of the plurality of top foil parts in the circumferential direction is a fixed end fixed to the first boss end surface 71a, while the other end is a free end.

The thrust bump foil 94 is configured by, for example, a plurality of fan-shaped bump foil parts arranged side by side in the circumferential direction of the rotating shaft 12, and has an annular shape (annular in detail). The plurality of bump foil parts have a convex portion that is convex in the axial direction Z of the rotating shaft 12, and the convex portion and the thrust top foil 93 (specifically, a plurality of top foil parts) are in contact with each other. In this state, it is fixed to the first boss end surface 71a. The thrust bump foil 94 elastically supports the thrust top foil 93 in a state in which the thrust top foil 93 can be displaced in the axial direction Z of the rotary shaft 12 by elastically deforming or restoring the original shape so that the convex portion is crushed. is doing. A thrust gap 95 is formed between the thrust top foil 93 and the thrust bump foil 94. The thrust gap 95 is open in the radial direction of the rotating shaft 12. That is, the fluid can flow between the radially inner side and the radially outer side of the first thrust bearing 91 via the thrust gap 95.

According to this configuration, when the rotating shaft 12 is rotated, the rotor 50 is in the non-contact state in which a gap is formed between the thrust top foil 93 and the first rotor end surface 50a by dynamic pressure, and the first thrust bearing 91 ( Specifically, it is supported by a thrust top foil 93). In this case, the first thrust bearing 91 receives a thrust force acting in the axial direction Z of the rotary shaft 12.

Here, the outer diameter of the first thrust bearing 91, specifically, the outer diameters of the thrust top foil 93 and the thrust bump foil 94 are set to be the same as the outer diameters of the rotor 50 and the first boss 71. The inner diameter of the first thrust bearing 91, specifically, the inner diameter of the thrust top foil 93 and the thrust bump foil 94 is set larger than the outer diameter of the main body portion 12 a of the rotating shaft 12. Therefore, an inner space A5 that communicates with the thrust gap 95 is formed on the radially inner side of the rotary shaft 12 with respect to the first thrust bearing 91, specifically between the first thrust bearing 91 and the rotary shaft 12. Yes. And the edge part near the 1st rotor end surface 50a among the both ends of the axial direction Z of the 1st radial bearing 81 is exposed to inner space A5 of the 1st thrust bearing 91. FIG. That is, the thrust gap 95 and the radial gap 85 communicate with each other via the inner space A5 of the first thrust bearing 91. The inner space A5 corresponds to “a space formed on the radially inner side of the rotation shaft with respect to the thrust bearing”.

Incidentally, as shown in FIG. 2, in the present embodiment, the inner diameter of the first thrust bearing 91 is set smaller than the inner diameter of the first boss 71. In other words, the inner peripheral end 91 a of the first thrust bearing 91 is spaced apart from the outer peripheral surface 12 c of the rotating shaft 12 and protrudes radially inward of the rotating shaft 12 from the inner peripheral surface 71 b of the first boss 71. Yes.

As shown in FIG. 1, the centrifugal compressor 10 constitutes a part of the vehicle air conditioner 100. That is, the fluid to be compressed by the centrifugal compressor in the present embodiment is a refrigerant.
In addition to the centrifugal compressor 10, the vehicle air conditioner 100 includes a condenser 101, a gas-liquid separator 102, an expansion valve 103, and an evaporator 104. The condenser 101, the gas-liquid separator 102, the expansion valve 103, and the evaporator 104 are connected via a pipe. The condenser 101 is connected to the first discharge port 33, and the evaporator 104 is connected to the second suction port 60. The vehicle air conditioner 100 also includes a pipe 105 that connects the second discharge port 36 and the first suction port 30.

Next, the flow of fluid in the centrifugal compressor 10 and the vehicle air conditioner 100 configured as described above will be described as an operation of the present embodiment.
When the impellers 14 and 15 rotate with the rotation of the rotating shaft 12, a relatively low pressure fluid (hereinafter referred to as suction fluid) discharged from the evaporator 104 is sucked from the second suction port 60. In this case, the motor chamber A3 is a low pressure space. The suction fluid sucked into the motor chamber A3 goes to the second impeller chamber A2. The suction fluid is sent from the second impeller chamber A2 to the second discharge chamber 35 through the second diffuser flow path 34 by the centrifugal action of the second impeller 15 and discharged from the second discharge port 36. The pressure of the fluid existing in the second discharge chamber 35 is higher than the pressure of the suction fluid. The fluid discharged from the second discharge port 36 is referred to as an intermediate pressure fluid.

Part of the suction fluid in the motor chamber A3 is a first and second thrust bearing 91 provided between the first and second rotor end faces 50a and 50b and the first and second boss end faces 71a and 72a. , 92 and the first and second radial bearings 81, 82 through the thrust gaps 95 and the inner space A 5 of the first and second thrust bearings 91, 92. In such a situation, when the rotary shaft 12 rotates, dynamic pressure is generated in the first and second thrust bearings 91 and 92 and the first and second radial bearings 81 and 82. As a result, the rotary shaft 12 is rotated by the rotary shaft. 12 is supported in a non-contact manner in both the radial direction and the axial direction Z. In this case, the thrust force is received by the first and second thrust bearings 91 and 92.

Further, as shown in FIG. 1, the intermediate pressure fluid is sucked into the first suction port 30 via the pipe 105. The intermediate pressure fluid is sent from the first impeller chamber A1 to the first discharge chamber 32 through the first diffuser flow path 31 by the centrifugal action of the first impeller 14 and discharged from the first discharge port 33. The pressure of the discharge fluid discharged from the first discharge port 33 is higher than the pressure of the intermediate pressure fluid.

According to the embodiment described above in detail, the following effects are obtained.
(1) The centrifugal compressor 10 has a rotating shaft 12 and a rotor 50 attached to the rotating shaft 12, and rotates by rotating the rotating shaft 12 with an electric motor 13 that rotates the rotating shaft 12. Impellers 14 and 15 for compressing fluid, and a housing 11 in which the rotary shaft 12, the electric motor 13, and the impellers 14 and 15 are accommodated. The centrifugal compressor 10 includes first and second bosses 71 and 72 that are provided in the housing 11 and through which the rotary shaft 12 is inserted.

Between the 1st boss | hub 71 and the rotating shaft 12, the 1st radial bearing 81 which supports the rotating shaft 12 rotatably is provided, and between the 2nd boss | hub 72 and the rotating shaft 12, a rotating shaft is provided. A second radial bearing 82 that rotatably supports 12 is provided.

The rotor 50 has first and second rotor end faces 50a and 50b located on opposite sides in the axial direction Z of the rotary shaft 12. The first rotor end surface 50 a faces the first boss end surface 71 a, which is the end surface of the first boss 71 in the axial direction Z of the rotation shaft 12, in the axial direction Z of the rotation shaft 12. The second rotor end surface 50 b faces the second boss end surface 72 a that is the end surface of the second boss 72 in the axial direction Z of the rotating shaft 12 in the axial direction Z of the rotating shaft 12.

The first and second thrust bearings 91 and 92 for receiving the thrust force are provided between the first and second rotor end faces 50a and 50b and the first and second boss end faces 71a and 72a, respectively.

According to such a configuration, the rotor 50 functions as a thrust liner that supports the first and second thrust bearings 91 and 92. Accordingly, it is possible to reduce the windage loss as compared with a configuration in which a dedicated thrust liner is provided and both the rotor 50 and the thrust liner rotate. Therefore, efficiency can be improved.

In order to suppress wear, a space is usually formed between the rotating rotor 50 and the first and second bosses 71 and 72 that do not rotate. The space tends to be a dead space. In contrast, in the present embodiment, the first and second thrust bearings 91 and 92 are provided between the rotor 50 and the first and second bosses 71 and 72, respectively. Effective utilization can be achieved. Moreover, since it is not necessary to provide a dedicated chamber for accommodating the first and second thrust bearings 91 and 92 and the thrust liner, the centrifugal compressor 10 can be reduced in size.

(2) Furthermore, in the configuration in which the thrust liner is provided at the base end portion of the rotating shaft 12, the direction in which the assembly direction during manufacture is directed from the first and second impellers 14 and 15 to the electric motor 13 and the direction are It is necessary to assemble from two directions, the opposite direction. On the other hand, in the present embodiment, the assembly direction may be only one direction from the first and second impellers 14 and 15 toward the electric motor 13. Thereby, manufacture of the centrifugal compressor 10 can be facilitated.

(3) The first and second thrust bearings 91 and 92 are provided on both sides of the rotor 50 in the axial direction Z of the rotating shaft 12. Specifically, the first and second bosses 71 and 72 are arranged so as to face each other in the axial direction Z of the rotary shaft 12 via the rotor 50. A first thrust bearing 91 is provided between the first boss end surface 71 a of the first boss 71 and the first rotor end surface 50 a that are opposed to each other in the axial direction Z of the rotation shaft 12. A second thrust bearing 92 is provided between the second boss end surface 72a of the second boss 72 facing the direction Z and the second rotor end surface 50b.

According to such a configuration, it is possible to receive both the thrust force in the first direction from the first thrust bearing 91 toward the second thrust bearing 92 and the thrust force in the second direction opposite to the first direction.

(4) The rotor 50 includes a plurality of electromagnetic steel plates 51 stacked in the axial direction Z of the rotating shaft 12, and first and second clamping plates 52 that hold the plurality of electromagnetic steel plates 51 from the axial direction Z of the rotating shaft 12, 53, and a plurality of electromagnetic steel plates 51 and rivets 54 for connecting the first and second sandwiching plates 52 and 53 to each other. The rivets 54 are a plurality of electromagnetic steel plates 51 and first and second sandwiching plates 52 and 53, and a first body portion 54a inserted into the first and second sandwiching plates 52 and 53, and a first portion provided at both end portions in the axial direction Z of the rotary shaft 12 in the first body portion 54a. And second heads 54b and 54c.

The rotor 50 includes first and second abutting surfaces 55a and 56a that abut on the sandwiching outer surfaces 52c and 53c of the first and second sandwiching plates 52 and 53, and first and second abutting surfaces 55a and 56a. Has first and second spacers 55, 56 having first and second rotor end faces 50a, 50b disposed on opposite sides.

Furthermore, the first and second spacers 55 and 56 have first and second recesses 55b and 56b as first and second accommodation portions in which the first and second head portions 54b and 54c are accommodated. . According to such a configuration, the first and second thrust bearings 91 and 92 are disposed between the first and second spacers 55 and 56 and the first and second bosses 71 and 72, respectively.

In this case, the first and second heads 54b and 54c of the rivet 54 are accommodated in the first and second recesses 55b and 56b. Accordingly, the first and second heads 54b and 54c are less likely to get in the way of the first and second thrust bearings 91 and 92.

Therefore, in the configuration in which the plurality of electromagnetic steel plates 51 and the clamping plates 52 and 53 are connected by the rivets 54, the first and second thrust bearings 91 and 92 can be suitably installed.
In particular, when the thrust bearings 91 and 92 are non-contact dynamic pressure bearings that receive a thrust force in a non-contact manner due to the dynamic pressure generated when the rotor 50 rotates, the fluid generated when the rotor 50 rotates by the heads 54b and 54c. If the flow is disturbed, the thrust force pressure may be disturbed.

On the other hand, in the present embodiment, the first and second heads 54b and 54c are accommodated in the first and second recesses 55b and 56b, and thus are caused by the first and second heads 54b and 54c. Disturbance of fluid flow is unlikely to occur. Accordingly, it is possible to suppress inconvenience that the thrust force receiving pressure is hindered due to the configuration for connecting the plurality of electromagnetic steel plates 51 and the first and second clamping plates 52 and 53.

(5) Here, for example, it is conceivable to form recesses in the first and second clamping plates 52 and 53. However, due to the characteristics of the rivet 54, it is necessary to perform a caulking process that crushes the distal end portion of the inserted body portion 54a to form a head portion. The caulking process is difficult to be performed if the first and second clamping plates 52 and 53 have a recess, and the inconvenience that the connection (caulking) by the rivet 54 is insufficient is likely to occur.

In contrast, in the present embodiment, since the first and second spacers 55 and 56 are provided separately from the first and second clamping plates 52 and 53, the first and second spacers 55 and 56 are provided after the caulking process. The second spacers 55 and 56 may be attached. Thereby, the said inconvenience can be suppressed.

(6) The electromagnetic steel plate 51 and the first and second spacers 55 and 56 are annular when viewed from the axial direction Z of the rotary shaft 12. The first and second thrust bearings 91 and 92 have an annular shape overlapping the first and second spacers 55 and 56 when viewed from the axial direction Z of the rotary shaft 12.

According to such a configuration, the centrifugal force generated in the rotor 50 at the time of rotation can be suppressed from fluctuating according to the position in the circumferential direction, so that the rotor 50 can be stably rotated. In addition, since the first and second thrust bearings 91 and 92 have an annular shape corresponding to the electromagnetic steel plate 51 and the first and second spacers 55 and 56, the first and second thrust bearings are compared with, for example, an elliptical shape. The area of the thrust bearings 91 and 92 can be easily increased. Thereby, the force which the 1st and 2nd thrust bearings 91 and 92 can receive pressure can be raised.

(7) The first and second thrust bearings 91 and 92 are driven by the dynamic pressure generated by the rotation of the rotor 50, and the first and second thrust bearings 91 and 92 (specifically, the thrust top foil 93) and the first and second rotors. This is a non-contact type dynamic pressure bearing that receives a thrust force in a non-contact state in which gaps are formed between the end surfaces 50a and 50b. In this case, if the first and second rotor end faces 50a and 50b are uneven, the first and second rotor end faces 50a and 50b and the first and second thrust bearings 91 and 92 are formed by the unevenness. Disturbances can occur in the fluid flow that creates dynamic pressure in between. Then, the problem that the said dynamic pressure becomes low may arise.

On the other hand, in the present embodiment, the first and second rotor end surfaces 50a and 50b are the plate surfaces of the first and second sandwiching plates 52 and 53 (specifically, the first and second sandwiching outer surfaces 52c and 53c). ). Thereby, since the said inconvenience can be suppressed, the 1st and 2nd thrust bearings 91 and 92 can be operated suitably.

(8) The first and second thrust bearings 91 and 92 are disposed at positions closer to the first and second rotor end surfaces 50a and 50b than the first and second boss end surfaces 71a and 72a, respectively. Sometimes a thrust top foil 93 is provided to support the rotor 50 in a non-contact state.

The first and second thrust bearings 91 and 92 are disposed closer to the first and second boss end surfaces 71a and 72a than the first and second rotor end surfaces 50a and 50b, and are elastically deformed to cause thrust. A thrust bump foil 94 is provided for supporting the top foil 93 in a state displaceable in the axial direction Z of the rotary shaft 12. According to such a configuration, the thrust force can be suitably received by the elastic deformation of the thrust bump foil 94.

Further, when vibration in the axial direction Z of the rotary shaft 12 occurs in the centrifugal compressor 10, the vibration is absorbed by the elastic deformation of the thrust bump foil 94. Thereby, the situation where the first and second rotor end faces 50a and 50b and the first and second boss end faces 71a and 72a slide due to the vibration in the axial direction Z of the rotating shaft 12 can be suppressed. Therefore, it can respond suitably to vibration.

(9) The first and second radial bearings 81 and 82 are respectively provided with respect to the radial top foil 83 and the radial top foil 83 that are provided radially outside the rotating shaft 12 with respect to the outer peripheral surface 12 c of the rotating shaft 12. And a radial bump foil 84 provided on the radially outer side of the rotary shaft 12. The radial top foil 83 supports the rotating shaft 12 in a non-contact state when the rotating shaft 12 rotates. The radial bump foil 84 elastically supports the radial top foil 83. The first and second thrust bearings 91 and 92 have an annular shape having an inner diameter longer than the diameter of the rotary shaft 12, and the inner side is radially inward of the rotary shaft 12 with respect to the first and second thrust bearings 91 and 92. A space A5 is formed.

In this configuration, the radial gap 85 opened in the axial direction Z of the rotary shaft 12 in the first radial bearing 81 and the thrust gap 95 opened in the radial direction of the rotary shaft 12 in the first thrust bearing 91 are the first thrust bearing. It communicates via 91 inner space A5.

Thereby, the fluid in the motor chamber A3 (suction fluid in the present embodiment) is supplied to the first radial bearing 81 through the thrust gap 95 and the inner space A5 of the first thrust bearing 91. Therefore, a necessary dynamic pressure is generated in the first radial bearing 81 when the rotary shaft 12 rotates.

Therefore, inconveniences that may occur due to the provision of the first thrust bearing 91 between the first boss end surface 71a and the first rotor end surface 50a, more specifically, the fluid to the first radial bearing 81 by the first thrust bearing 91. Is restricted, and the operation of the first radial bearing 81 can be prevented from being hindered. The same applies to the second radial bearing 82 and the second thrust bearing 92.

(10) In particular, the inner peripheral end 91a of the first thrust bearing 91 is separated from the outer peripheral surface 12c of the rotary shaft 12, and is directed radially inward of the rotary shaft 12 relative to the inner peripheral surface 71b of the first boss 71. Protruding. Thereby, since the area improvement of the 1st thrust bearing 91 can be aimed at, the thrust force which can receive pressure can be raised. The same applies to the second thrust bearing 92.

(11) The centrifugal compressor 10 defines an inverter 61 that drives the electric motor 13 and an inverter chamber A4 that houses the inverter 61, and is an inverter that is attached to the housing 11 from the axial direction Z of the rotary shaft 12. And a case 62. The housing 11 houses the electric motor 13 and has a motor chamber A3 in which fluid is sucked from the second suction port 60, and an end plate 42 as a partition wall that partitions the motor chamber A3 and the inverter chamber A4. ing.

According to such a configuration, the inverter 61 exchanges heat with the fluid in the motor chamber A3 via the end plate. Thereby, the inverter 61 can be cooled using the fluid in the motor chamber A3.

In particular, in the present embodiment, a thrust chamber for accommodating the thrust bearing and the thrust liner is not provided between the inverter chamber A4 and the motor chamber A3. For this reason, the inverter 61 can be suitably cooled using the fluid in the motor chamber A3. Therefore, the heat generation of the inverter 61 can be suitably suppressed.

(12) The centrifugal compressor 10 includes a first impeller 14 and a second impeller 15 that are disposed so that the base end surfaces 14a and 15a face each other. The suction fluid is sucked into the motor chamber A3 from the second suction port 60. The motor chamber A3 and the second impeller chamber A2 that houses the second impeller 15 are in communication with each other, and the second impeller 15 compresses the suction fluid sucked from the motor chamber A3 into the second impeller chamber A2. . The first impeller 14 compresses the intermediate pressure fluid compressed by the second impeller 15.

According to this configuration, the motor chamber A3 is filled with the suction fluid having a relatively low pressure. Thereby, the windage loss of the rotor 50 provided in the motor chamber A3 can be reduced.

In addition, you may change the said embodiment as follows.
As shown in FIG. 3, the first discharge port 33 and the second suction port 60 may be omitted. In this case, the centrifugal compressor 10 may include an intermediate pressure port 110 that communicates the first discharge chamber 32 and the motor chamber A3. The intermediate pressure port 110 passes through the intermediate part 23, the second part 22 and the bottom 41 a of the motor housing 41 in the axial direction Z of the rotary shaft 12. The condenser 101 is connected to the second discharge port 36, and the first suction port 30 is connected to the evaporator 104.

According to this configuration, the fluid discharged from the evaporator 104 and sucked from the first suction port 30 is the first impeller chamber A1 → the first diffuser flow path 31 → the first discharge chamber 32 → the intermediate pressure port 110 → the motor. It passes through chamber A3 → second impeller chamber A2 → second diffuser flow path 34 → second discharge chamber 35 and is discharged from the second discharge port 36. In this case, the motor chamber A3 is filled with the intermediate pressure fluid.

One of the first and second thrust bearings 91 and 92 may be omitted.
The structure of the first and second thrust bearings 91 and 92 may be different.
The first boss 71 may be provided with a through hole penetrating in the radial direction of the rotating shaft 12. The through hole may communicate the space between the first radial bearing 81 and the end plate 42 with the space on the radially outer side of the rotary shaft 12 with respect to the first boss 71. Thereby, the fluid can be more suitably supplied to the first radial bearing 81.

○ The outer diameter of the rotor 50 may be different from the outer diameter of the first and second bosses 71, 72. In this case, the outer diameters of the thrust bearings 91 and 92 are preferably set equal to or shorter than the shorter one of the outer diameter of the rotor 50 and the outer diameters of the first and second bosses 71 and 72.

In addition, the inner diameters of the first and second thrust bearings 91 and 92 may be set to be equal to or larger than the inner diameters of the first and second bosses 71 and 72.
The magnetic steel sheet 51 may be non-circular when viewed from the axial direction Z of the rotating shaft 12. In this case, the saliency of the rotor 50 can be increased. In such a configuration, the spacers 55 and 56 are preferably annular when viewed from the axial direction Z of the rotating shaft 12. As a result, it is possible to suitably receive the thrust force using the first and second thrust bearings 91 and 92 while increasing the saliency of the rotor 50.

The first and second sandwiching plates 52 and 53 and the first and second spacers 55 and 56 may be non-annular or the boss 71 according to the shape of the electromagnetic steel plate 51. , 72 may also be a non-circular cylinder as viewed from the axial direction Z of the rotary shaft 12.

○ The first and second spacers 55 and 56 may be omitted. In this case, the first and second sandwiching outer surfaces 52c and 53c of the first and second sandwiching plates 52 and 53 constitute the first and second rotor end surfaces 50a and 50b. Moreover, you may form the recessed part which accommodates the 1st and 2nd head 54b, 54c in the 1st and 2nd clamping outer surface 52c, 53c of the 1st and 2nd clamping plates 52,53. Further, only one of the first and second spacers 55 and 56 may be omitted.

The accommodating portion is not limited to the concave portion, and may be a through-hole penetrating in the plate thickness direction of the first and second spacers 55 and 56, for example.
The configuration for connecting the plurality of electromagnetic steel plates 51 and the first and second clamping plates 52 and 53 and the configuration for integrally rotating these with the rotor 50 are not limited to the rivets 54 and are arbitrary. In short, the plurality of electromagnetic steel plates 51 and the first and second sandwiching plates 52 and 53 may be fixed to the rotary shaft 12 so as to rotate integrally with the rotor 50 in a state of being connected to each other.

○ The first and second thrust bearings 91 and 92 are foil type having a thrust top foil 93 and a thrust bump foil 94. However, the present invention is not limited to this, and if it can receive a thrust force, its specific configuration Is optional. The same applies to both radial bearings 81 and 82.

One of the first and second impellers 14 and 15 may be omitted. In this case, the diffuser flow path and the discharge chamber corresponding to the omitted impeller may be omitted.
O The object for mounting the centrifugal compressor 10 is not limited to the vehicle, but is arbitrary.

The centrifugal compressor 10 of the embodiment is used in a part of the vehicle air conditioner 100, but is not limited to this, and may be used for other purposes. For example, when the vehicle is a fuel cell vehicle (FCV: Fuel Cell Vehicle) equipped with a fuel cell, the centrifugal compressor 10 may be used in a supply device that supplies air to the fuel cell. In short, the fluid to be compressed may be a refrigerant or air, and the fluid device is not limited to the vehicle air conditioner 100 and is arbitrary.

Claims (8)

A rotation axis;
An electric motor having a rotor attached to the rotating shaft and rotating the rotating shaft;
An impeller that compresses the fluid by rotating with rotation of the rotating shaft;
A housing in which the rotating shaft, the electric motor, and the impeller are housed;
A cylindrical boss provided in the housing and through which the rotating shaft is inserted;
A radial bearing provided between the boss and the rotating shaft and rotatably supporting the rotating shaft;
A centrifugal compressor comprising:
The rotor has a rotor end surface that is an end surface in the axial direction of the rotating shaft;
The boss has a boss end surface which is an end surface in the axial direction of the rotating shaft,
The rotor end surface and the boss end surface are opposed to each other in the axial direction of the rotation shaft,
The centrifugal compressor includes a thrust bearing that receives a thrust force generated by rotation of the impeller between the rotor end surface and the boss end surface. The boss is a first boss, and the centrifugal compressor further includes a second boss that is paired with the first boss, and the first boss and the second boss are connected to the rotating shaft via the rotor. Arranged so as to face each other in the axial direction,
The rotor has a first rotor end surface as the rotor end surface, and a second rotor end surface located on the opposite side of the first rotor end surface in the axial direction of the rotating shaft,
The first boss has a first boss end surface as the boss end surface, and the first boss end surface and the first rotor end surface are opposed to each other in the axial direction of the rotation shaft,
The second boss has a second boss end surface as the boss end surface, and the second boss end surface and the second rotor end surface are opposed to each other in the axial direction of the rotation shaft,
The thrust bearing is a first thrust bearing provided between the first rotor end surface and the first boss end surface;
The centrifugal compressor according to claim 1, further comprising a second thrust bearing provided between the second rotor end face and the second boss end face. The rotor is
A plurality of electrical steel sheets laminated in the axial direction of the rotating shaft;
First and second clamping plates for clamping the plurality of electromagnetic steel plates from the axial direction of the rotary shaft;
The plurality of electromagnetic steel plates, the body portion inserted through the first and second clamping plates, and both end portions in the axial direction of the rotation axis of the body portion, the diameter of which is larger than that of the body portion A rivet having a first head and a second head provided on
A first contact surface that contacts the plate surface of the first sandwiching plate, the first rotor end surface disposed on the opposite side of the first contact surface, and the first head housing the first head. A first spacer having a receiving portion;
A second contact surface that contacts the plate surface of the second clamping plate, the second rotor end surface disposed on the opposite side of the second contact surface, and a second housing that houses the second head. A second spacer having a receiving portion;
The centrifugal compressor according to claim 2 provided with. The first thrust bearing is a non-contact that receives the thrust force in a non-contact state in which a gap is formed between the first thrust bearing and the first rotor end surface by dynamic pressure generated by the rotation of the rotor. Type dynamic pressure bearing,
The second thrust bearing is a non-contact that receives the thrust force in a non-contact state in which a gap is formed between the second thrust bearing and the second rotor end surface due to a dynamic pressure generated by rotation of the rotor. Type dynamic pressure bearing,
The centrifugal compressor according to claim 3, wherein the first rotor end surface and the second rotor end surface are flatter than the plate surfaces of the first and second clamping plates. The thrust bearing is
A thrust top foil disposed between the boss end surface and the rotor end surface at a position closer to the rotor end surface than the boss end surface, and supporting the rotor in a non-contact state when the rotary shaft rotates;
Between the boss end face and the rotor end face, the thrust top foil is disposed in a position closer to the boss end face than the rotor end face, and is elastically deformed so that the thrust top foil can be displaced in the axial direction of the rotating shaft. And thrust bump foil
The centrifugal compressor according to any one of claims 1 to 4, further comprising: The radial bearing is
A radial top foil that is provided radially outside the rotary shaft with respect to the outer peripheral surface of the rotary shaft, and supports the rotary shaft in a non-contact state when the rotary shaft rotates;
A radial bump foil that is disposed radially outside the rotational axis with respect to the radial top foil and elastically supports the radial top foil;
With
The thrust bearing is an annular shape having an inner diameter longer than the diameter of the rotating shaft, and a space is formed on the radially inner side of the rotating shaft with respect to the thrust bearing,
A radial gap formed between the radial top foil and the radial bump foil and a thrust gap formed between the thrust top foil and the thrust bump foil communicate with each other through the space. The centrifugal compressor according to claim 5. A drive circuit for driving the electric motor;
A circuit case for housing the drive circuit, and a circuit case attached to the housing from an axial direction of the rotating shaft;
With
The housing is
A motor chamber that houses the electric motor and into which fluid is sucked;
A partition wall that partitions the motor chamber and the circuit chamber;
Have
The centrifugal compressor according to any one of claims 1 to 6, wherein the drive circuit exchanges heat with the fluid in the motor chamber via the partition wall. The centrifugal compressor according to claim 6, wherein an inner peripheral end of the thrust bearing protrudes radially inward of the rotary shaft from an inner peripheral surface of the boss.

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