JP2017078356A - Centrifugal compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a centrifugal compressor having efficiency which can be improved.SOLUTION: A centrifugal compressor 10 comprises a rotary shaft 12, an electric motor 13 having a rotor 50 mounted on the rotary shaft 12, impellers 14, 15, a housing 11 in which the rotary shaft 12, the electric motor 13 and the impellers 14, 15 are housed, and a pair of bosses 71, 72 which is provided in the housing 11 and through which the rotary shaft 12 is inserted. Boss end faces 71a, 72a of the bosses 71, 72 and rotor end faces 50a, 50b of the rotor 50 are opposed to each other in an axial direction Z of the rotary shaft 12. Between the rotor end faces 50a, 50b and the boss end faces 71a, 72a, thrust bearings 91, 92 are provided for receiving thrust force, respectively.SELECTED DRAWING: Figure 1

Description

  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. (For example, refer to 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.
This invention is made | formed in view of the situation mentioned above, The objective is to provide the centrifugal compressor which can aim at the improvement of 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 A radial bearing that rotatably supports the rotating shaft, and a rotor end surface that is an end surface in the axial direction of the rotating shaft in the rotor, and a boss that is the end surface in the axial direction of the boss A thrust bearing that receives a thrust force generated by the rotation of the impeller is provided between the end surface of the rotor and the end surface of the boss. And said that you are.

  According to this configuration, since the thrust bearing is provided between the rotor end surface and the boss end surface, the rotor functions as a thrust liner. As a result, it is possible to reduce the windage loss as compared with a configuration in which a thrust liner is separately provided and both the rotor and the thrust liner rotate. Therefore, efficiency can be improved. In addition, since a thrust bearing is provided between the rotor and the boss, which is likely to become a dead space, it is possible to effectively use the space, and in comparison with a configuration in which a thrust chamber or the like for accommodating the thrust bearing is provided, The size of the centrifugal compressor can be reduced.

  In the centrifugal compressor, a pair of the bosses are provided in a state of being opposed to each other in the axial direction via the rotor, and a first boss end surface that is the boss end surface of the first boss among the pair of bosses. And a first rotor end surface of both end surfaces in the axial direction of the rotor are opposed to the axial direction, a second boss end surface that is the boss end surface of a second boss among the pair of bosses, and Of the both end faces in the axial direction of the rotor, the second rotor end face opposite to the first rotor end face is opposed to the axial direction, and the centrifugal compressor serves as the thrust bearing as the first rotor. It is good to have the 1st thrust bearing provided between the end face and the 1st boss end face, and the 2nd thrust bearing provided between the 2nd rotor end face and the 2nd boss end face. . According to this configuration, since the thrust bearings are provided on both sides in the axial direction with respect to the rotor, the thrust force in the direction from the first thrust bearing toward the second thrust bearing, and the second thrust bearing to the first thrust Both thrust forces in the direction toward the bearing can be received.

  In the centrifugal compressor, the rotor includes a plurality of electromagnetic steel plates stacked in the axial direction, a pair of clamping plates that sandwich the plurality of electromagnetic steel plates from the axial direction, the plurality of electromagnetic steel plates and the pair of electromagnetic steel plates. A body portion inserted through the holding plate, and a first head portion and a second head portion that are larger in diameter than the body portion and are provided at both ends of the body portion in the axial direction. A rivet, a first contact surface that contacts the plate surface of the first sandwiching plate of the pair of sandwiching plates, the first rotor end surface disposed on the opposite side of the first contact surface, and the first A first spacer having a first accommodating portion in which one head is accommodated; a second abutting surface that abuts a plate surface of a second sandwiching plate of the pair of sandwiching plates; and the second abutting surface Has an end surface of the second rotor disposed on the opposite side and a second accommodating portion in which the second head is accommodated. A second spacer that may be provided with a. According to such a configuration, the thrust bearing is disposed between the spacer having the rotor end surface and the boss. And the head is accommodated in the accommodating part of a spacer. As a result, the head is unlikely to get in the way of the thrust bearing. Therefore, in a configuration in which a rivet having a head is provided, the thrust bearing can be preferably installed. In addition, the accommodating part can consider the recessed part, a through-hole, etc. which were dented from the 1st contact surface, for example.

  In the centrifugal compressor, the first thrust bearing is 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 rotation of the rotor. A non-contact dynamic pressure bearing that receives a thrust force, wherein the second thrust bearing has a gap formed between the second thrust bearing and the second rotor end surface by the dynamic pressure generated by the rotation of the rotor. It is a non-contact dynamic pressure bearing that receives the thrust force in a non-contact state, and the first rotor end surface and the second rotor end surface may be flatter than the plate surfaces of the pair of clamping plates. According to such a configuration, the rotor end surface on which the thrust bearing is installed is flatter than the plate surface of the clamping plate, so that the thrust bearing that is a non-contact dynamic pressure bearing can be suitably operated.

  With respect to the centrifugal compressor, the thrust bearing is disposed closer to the rotor end surface than the boss end surface, and a thrust top foil that supports the rotor in a non-contact state when the rotating shaft rotates, and more than the rotor end surface It is good to provide the thrust bump foil which is arranged in the boss end face side, and supports the thrust top foil in the state displaceable in the axial direction by elastically deforming. According to this configuration, when vibration is generated in the centrifugal compressor, the vibration is absorbed by elastic deformation of the thrust bump foil. Thereby, it can respond suitably to a vibration.

  In the centrifugal compressor, the radial bearing 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 foil, and a radial bump foil that is disposed radially outward of the rotary shaft with respect to the radial top foil and elastically supports the radial top foil, wherein the thrust bearing has a diameter greater than that of the rotary shaft. Is a ring having a long inner diameter, a space is formed radially inward of the rotary shaft with respect to the thrust bearing, and a radial gap formed between the radial top foil and the radial bump foil, The thrust gap formed between the thrust top foil and the thrust bump foil is through the space. It may have passed. According to such a configuration, a part of the fluid in the housing is supplied to the radial bearing through the thrust gap and the space inside the thrust bearing. Thereby, when a rotating shaft rotates, a dynamic pressure required in a radial bearing will generate | occur | produce. Therefore, inconveniences that may be caused by the provision of the thrust bearing between the boss and the rotor, specifically, the supply of fluid to the radial bearing by the thrust bearing can be suppressed.

  The centrifugal compressor includes a drive circuit that drives the electric motor, and a circuit case that partitions a circuit chamber that houses the drive circuit, and is attached to the housing from the axial direction. The housing includes a motor chamber in which the electric motor is accommodated and fluid is sucked, and a partition wall that partitions the motor chamber and the circuit chamber, and the drive circuit is interposed via the partition wall. The heat exchange with the fluid in the motor chamber is good. According to this configuration, the drive circuit can be cooled using the fluid in the motor chamber. In particular, according to this configuration, since there is no thrust chamber for accommodating the thrust bearing between the circuit chamber and the motor chamber in which fluid exists, the drive circuit can be suitably cooled.

  According to the present invention, efficiency can be improved.

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. In addition, in FIG. 1 etc., the rotating shaft 12 is shown with 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 two impellers 14 and 15 attached to the rotating shaft 12, as housed in a housing 11. 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 to which both impellers 14 and 15 are attached.

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

  The first part 21 has a substantially cylindrical shape having a first comp through hole 21 a penetrating in the axial direction Z of the rotating shaft 12. The first comp through-holes 21 a are open at both end faces 21 b and 21 c in the axial direction Z of the rotary shaft 12 in the first part 21. The first comp through hole 21a is a truncated cone shape that gradually decreases in diameter from the opening of one end surface 21b of the both end surfaces 21b and 21c in contact with the intermediate part 23 to the middle position in the axial direction Z of the rotary shaft 12. From the midway position to the opening of the other end surface 21c on the opposite side to the one end surface 21b, a cylindrical shape with the same diameter is formed.

  The second part 22 has a substantially cylindrical shape with the axial direction Z of the rotating shaft 12 as the axial direction. Of the two end faces 22a, 22b of the second part 22 in the axial direction Z of the rotary shaft 12, the other end face 22b opposite to the one end face 22a in contact with the intermediate part 23 is recessed from the other end face 22b. 22c is formed. A second comp 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 comp through hole 22d has a truncated cone shape with a gradually reduced diameter from the opening on the intermediate part 23 side to the middle position in the axial direction Z of the rotating shaft 12, and the opening on the intermediate part 23 side from the middle position. Up to the opening on the opposite side, the cylinder has the same diameter.

  The intermediate part 23 has a substantially disk shape in which the axial direction Z of the rotary shaft 12 is the plate thickness direction. The intermediate part 23 is a first intermediate part end face 23a that is in contact with the one end face 21b of the first part 21, and an end face opposite to the first intermediate part end face 23a, and is an end face 22a of the second part 22. And a second intermediate part end surface 23b in contact with the second intermediate part end surface 23b. The first impeller chamber A1 is defined by the inner surface of the first comp 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 comp 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 is formed with 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 comp 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 comp 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) is formed with a first suction port 30 through which fluid is sucked. The first suction port 30 is an opening on the other end surface 21c side in the first comp through hole 21a. That is, the first comp 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 cylindrical 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 opening end of the motor housing 41 is in contact with the first plate surface 42 a of the end plate 42, and the opening of the motor housing 41 is closed by the end plate 42. It is. 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 rotating shaft 12 (specifically, the main body portion 12 a of the rotating shaft 12). The rotor 50 as a whole has a cylindrical shape (specifically, a cylindrical shape) in which the axial direction Z of the rotating shaft 12 is the axial direction, and has both rotor end surfaces 50 a and 50 b that are both end surfaces of the rotating shaft 12 in the axial direction Z. doing. The rotor 50 includes a plurality of electromagnetic steel plates 51 stacked in the axial direction Z of the rotating shaft 12 and a pair of clamping plates 52 and 53 that clamp the plurality of electromagnetic steel plates 51 from the axial direction Z of the rotating shaft 12. . In the present embodiment, the electromagnetic steel plate 51 and the both sandwiching plates 52 and 53 have the same shape, and are specifically annular when viewed from the axial direction Z of the rotating 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 rivet 54 as a connecting member that connects a plurality of electromagnetic steel plates 51 and a pair of clamping plates 52 and 53. The rivet 54 includes a body portion 54a inserted through a plurality of electromagnetic steel plates 51 and a pair of clamping plates 52 and 53, and a first head portion 54b and a second head portion provided at both end portions in the axial direction Z of the body portion 54a. Part 54c. One of the heads 54b and 54c is formed in advance before caulking, and the other is formed by crushing the tip of the body 54a by caulking.

  The plurality of electromagnetic steel plates 51 and the pair of sandwiching plates 52 and 53 are connected by being sandwiched between both heads 54b and 54c. Specifically, through holes 51 a, 52 a, and 53 a that are communicated in the axial direction Z of the rotating shaft 12 are formed in the plurality of electromagnetic steel plates 51 and the pair of clamping plates 52 and 53. 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. Moreover, both heads 54b and 54c are diameter-expanded rather than each through-hole 51a, 52a, 53a. The heads 54b and 54c are hooked on the sandwiching outer surfaces 52c and 53c on the opposite side of the sandwiching inner surfaces 52b and 53b in contact with the electromagnetic steel plate 51 in the sandwiching plates 52 and 53. Thereby, the some electromagnetic steel plate 51 and a pair of clamping plates 52 and 53 are unitized. The pair of 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 pair of clamping plates 52 and 53 rotate integrally. In this case, the heads 54b and 54c protrude from the sandwiching outer surfaces 52c and 53c.

  As shown in FIG. 1, in the present embodiment, a plurality of rivets 54 are attached to be separated 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 spacers 55 and 56 provided on the outer side in the axial direction Z of the rotary shaft 12 with respect to the pair of sandwiching plates 52 and 53. The spacers 55 and 56 have, for example, a disk shape in which the axial direction Z of the rotary shaft 12 is the thickness direction, and the diameters of the spacers 55 and 56 are the same as those of the electromagnetic steel plate 51 and the pair of sandwiching plates 52 and 53. The spacers 55 and 56 are formed thicker than the 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 spacers 55 and 56 have recesses 55b and 56b as accommodating portions for accommodating the head portions 54b and 54c. The recesses 55b and 56b are recessed from the contact surfaces 55a and 56a toward the outside in the axial direction Z. The depth dimensions of the recesses 55b and 56b are set longer than the thicknesses of the heads 54b and 54c within a range shorter than the plate thickness of the spacers 55 and 56. For this reason, both rotor end surfaces 50a and 50b are flat surfaces on which recesses corresponding to the recesses 55b and 56b are not formed.

  The spacers 55 and 56 are disposed on the holding plates 52 and 53 in a state where the heads 54b and 54c are accommodated in the recesses 55b and 56b, and the contact surfaces 55a and 56a and the holding outer surfaces 52c and 53c are in contact. It is fixed. The specific fixing mode between the sandwiching plates 52 and 53 and the spacers 55 and 56 is arbitrary 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 both rotor end surfaces 50a and 50b than on the sandwiching outer surfaces 52c and 53c.

  A method for manufacturing the rotor 50 of the present 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 a pair of sandwiching plates 52 and 53, and an inserting step of inserting the body portion 54a of the rivet 54 into the laminated body. 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 by crushing the front-end | tip part (specifically the edge part on the opposite side to the head side among the both ends of the axial direction Z of the trunk | drum 54a) in the rivet 54. A crimping process for connecting the laminated bodies is provided. By the caulking process, a head is formed at the tip of the body 54a, and heads 54b and 54c are formed at both ends in the axial direction Z of the body 54a.

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

  As shown in FIG. 1, the electric motor 13 includes a stator 57 that is disposed on the radially outer side of the rotary shaft 12 with respect to the rotor 50 and is 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 the inverter chamber A4 that accommodates the inverter 61. The inverter case 62 has a bottomed cylindrical shape with one opening, 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 this configuration, the inverter 61 and the fluid in the motor chamber A <b> 3 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, a pair of bosses 71 and 72 into which the rotary shaft 12 (specifically, the main body 12 a) is inserted are provided in the motor chamber A <b> 3 that is the housing 11. The pair of bosses 71 and 72 have a cylindrical shape, specifically, a cylindrical shape having an inner diameter longer than the diameter of the main body portion 12 a of the rotating shaft 12 and an outer diameter that is the same as the outer diameter of the rotor 50. The axial lines of both bosses 71 and 72 coincide with the axial line of the main body 12a. The pair of bosses 71 and 72 are disposed to face each other in the axial direction Z of the rotary shaft 12 via the rotor 50.

  The first boss 71 stands up 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 rotating shaft 12 is defined as a first boss end surface 71a. The first boss end surface 71 a and the first rotor end surface 50 a are disposed 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 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 tip surface of the second boss 72, specifically, the end surface of the second boss 72 in the axial direction Z of the rotary shaft 12 is defined as a second boss end surface 72a. The second boss end surface 72 a and the second rotor end surface 50 b are disposed 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 in which 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.

  Note that the bottom communication hole 41 b is formed across both the portion overlapping the second boss 72 and the surrounding portion as 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 radial bearings 81 and 82 for rotatably supporting the rotary shaft 12.

  The radial bearings 81 and 82 are, for example, flexible non-contact 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 radially outside 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 two thrust bearings 91 and 92 that receive a thrust force generated by the rotation of both 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 thrust bearings 91 and 92 are thrust in a non-contact state in which gaps are formed between the thrust bearings 91 and 92 and the rotor end surfaces 50a and 50b by dynamic pressure generated by the rotation of the rotor 50. It is a non-contact hydrodynamic bearing that receives force.

  Both thrust bearings 91 and 92 have the same configuration except that they are bilaterally symmetric. 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 includes a thrust top foil 93 disposed closer to the first rotor end surface 50a than the first boss end surface 71a, and a thrust bump foil disposed closer to the first boss end surface 71a than the first rotor end surface 50a. 94.

  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 (in detail, an annular shape) as a whole. 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. 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 to be longer than the 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 this embodiment, the inner diameter of the first thrust bearing 91 is set shorter 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.

  A part of the suction fluid in the motor chamber A3 is supplied to thrust bearings 91 and 92 provided between the rotor end surfaces 50a and 50b and the boss end surfaces 71a and 72a. It is supplied to both radial bearings 81 and 82 through the thrust gap 95 and the inner space A5. In such a situation, when the rotating shaft 12 rotates, dynamic pressure is generated in the thrust bearings 91 and 92 and the radial bearings 81 and 82, and as a result, the rotating shaft 12 is in the radial direction and the axial direction Z of the rotating shaft 12. In both cases, it is supported in a non-contact manner. In this case, the thrust force is received by both 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 a pair of 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 rotor end surfaces 50 a and 50 b that are end surfaces in the axial direction Z of the rotary shaft 12. The rotor end surfaces 50 a and 50 b and bosses that are end surfaces in the axial direction Z of the rotary shaft 12 at the bosses 71 and 72. The end surfaces 71 a and 72 a are opposed to the axial direction Z of the rotating shaft 12. Thrust bearings 91 and 92 for receiving a thrust force are provided between the rotor end surfaces 50a and 50b and the boss end surfaces 71a and 72a.

  According to such a configuration, the rotor 50 functions as a thrust liner that supports the 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 non-rotating bosses 71 and 72. The space tends to be a dead space. On the other hand, in the present embodiment, since the thrust bearings 91 and 92 are provided between the rotor 50 and the bosses 71 and 72, it is possible to effectively use the dead space. Further, since it is not necessary to provide a dedicated chamber for accommodating the thrust bearings 91 and 92 and the thrust liner, the centrifugal compressor 10 can be reduced in size.

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

  (3) The thrust bearings 91 and 92 are provided on both sides of the rotor 50 in the axial direction Z of the rotary shaft 12. Specifically, the pair of bosses 71 and 72 are disposed 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 rotary shaft 12, a pair of clamping plates 52 and 53 that hold the plurality of electromagnetic steel plates 51 from the axial direction Z of the rotary shaft 12, A plurality of electromagnetic steel plates 51 and a rivet 54 for connecting a pair of clamping plates 52 and 53 are provided. The rivet 54 includes a body portion 54a inserted through the plurality of electromagnetic steel plates 51 and the sandwiching plates 52 and 53, and head portions 54b and 54c provided at both ends of the body portion 54a in the axial direction Z of the rotary shaft 12. have. The rotor 50 is a spacer having contact surfaces 55a and 56a that contact the sandwiched outer surfaces 52c and 53c of the sandwich plates 52 and 53, and rotor end surfaces 50a and 50b disposed on the opposite side of the contact surfaces 55a and 56a. 55, 56. Furthermore, the spacers 55 and 56 have recesses 55b and 56b as storage portions in which the heads 54b and 54c are stored. According to such a configuration, the thrust bearings 91 and 92 are disposed between the spacers 55 and 56 and the bosses 71 and 72. In this case, the heads 54b and 54c of the rivet 54 are accommodated in the recesses 55b and 56b. Thus, the heads 54b and 54c are less likely to get in the way of the thrust bearings 91 and 92. Therefore, in the configuration in which the plurality of electromagnetic steel plates 51 and the sandwiching plates 52 and 53 are connected by the rivets 54, the 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 by the dynamic pressure generated when the rotor 50 rotates, the flow of fluid generated when the rotor 50 rotates by the heads 54b and 54c. If disturbance occurs, the pressure receiving of the thrust force may be hindered.

  On the other hand, in the present embodiment, since the heads 54b and 54c are accommodated in the recesses 55b and 56b, the fluid flow is hardly disturbed due to the heads 54b and 54c. Thereby, it is possible to suppress the inconvenience that the thrust force receiving pressure is hindered due to the configuration for connecting the plurality of electromagnetic steel plates 51 and the sandwiching plates 52 and 53.

  (5) Here, for example, it is conceivable to form recesses in the sandwiching 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 perform if there are concave portions in the sandwiching plates 52 and 53, and the inconvenience that the connection (caulking) by the rivet 54 becomes insufficient is likely to occur.

  On the other hand, in the present embodiment, since the spacers 55 and 56 are provided separately from the pair of sandwiching plates 52 and 53, the spacers 55 and 56 may be attached after the caulking process. Thereby, the said inconvenience can be suppressed.

  (6) The electromagnetic steel plate 51 and the spacers 55 and 56 are annular when viewed from the axial direction Z of the rotary shaft 12. The thrust bearings 91 and 92 have an annular shape overlapping the spacers 55 and 56 when viewed from the axial direction Z of the rotary shaft 12. According to such a configuration, it is possible to suppress the centrifugal force generated in the rotor 50 during rotation from fluctuating according to the position in the circumferential direction, and thus it is possible to realize stable rotation of the rotor 50. In addition, since the thrust bearings 91 and 92 have an annular shape corresponding to the electromagnetic steel plates 51 and the spacers 55 and 56, the area of the thrust bearings 91 and 92 can be easily increased as compared with an elliptical shape or the like. Thereby, the force which thrust bearings 91 and 92 can receive pressure can be raised.

  (7) The thrust bearings 91 and 92 are non-contact in which gaps are formed between the thrust bearings 91 and 92 (specifically, the thrust top foil 93) and the rotor end surfaces 50a and 50b by dynamic pressure generated by the rotation of the rotor 50. It is a non-contact dynamic pressure bearing that receives a thrust force in the state. In this case, if irregularities are formed on the rotor end faces 50a and 50b, the irregularities may cause a disturbance in the flow of fluid that generates dynamic pressure between the rotor end faces 50a and 50b and the thrust bearings 91 and 92. . Then, the problem that the said dynamic pressure becomes low may arise.

  On the other hand, in this embodiment, the rotor end surfaces 50a and 50b are flatter than the plate surfaces of the sandwich plates 52 and 53 (specifically, the sandwich outer surfaces 52c and 53c). Thereby, since the said inconvenience can be suppressed, the thrust bearings 91 and 92 can be operated suitably.

  (8) Both thrust bearings 91 and 92 are disposed closer to the rotor end surfaces 50a and 50b than the boss end surfaces 71a and 72a, and include a thrust top foil 93 that supports the rotor 50 in a non-contact state when the rotating shaft 12 rotates. ing. Further, the thrust bearings 91 and 92 are disposed closer to the boss end surfaces 71a and 72a than the rotor end surfaces 50a and 50b, and can be displaced in the axial direction Z of the rotary shaft 12 by elastic deformation. The thrust bump foil 94 is supported. 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 elastic deformation of the thrust bump foil 94. Thereby, the situation where the rotor end surfaces 50a and 50b and the boss end surfaces 71a and 72a slide due to vibration in the axial direction Z of the rotating shaft 12 can be suppressed. Therefore, it can respond suitably to vibration.

  (9) The radial bearings 81 and 82 are respectively provided with a radial top foil 83 provided radially outward of the rotary shaft 12 with respect to the outer peripheral surface 12 c of the rotary shaft 12, and the rotary shaft 12 with respect to the radial top foil 83. And a radial bump foil 84 provided outside in the radial direction. 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. Both thrust bearings 91 and 92 have an annular shape having an inner diameter longer than the diameter of the rotary shaft 12, and an inner space A <b> 5 is formed on the radially inner side of the rotary shaft 12 with respect to both thrust bearings 91 and 92.

  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 (intake fluid in the present embodiment) is supplied to the first radial bearing 81 via 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 a thrust bearing and a 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 in which the base end surfaces 14a and 15a are arranged to 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. With 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.

O Either one of the thrust bearings 91 and 92 may be omitted.
The structure of both 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 and the outer diameter of the bosses 71 and 72 may be different. In this case, the outer diameters of the thrust bearings 91 and 92 are preferably set to be equal to or shorter than the shorter one of the outer diameter of the rotor 50 and the outer diameters of the bosses 71 and 72.

The inner diameters of the thrust bearings 91 and 92 may be set to be equal to or larger than the inner diameters of the 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. Thereby, it is possible to suitably receive the thrust force using the thrust bearings 91 and 92 while increasing the saliency of the rotor 50.

  However, the present invention is not limited to this, and the sandwiching plates 52 and 53 and the spacers 55 and 56 may be non-circular, and the bosses 71 and 72 are also in the axial direction Z of the rotary shaft 12 in accordance with the shape of the electromagnetic steel plate 51. It may be a non-circular cylinder as viewed from the top.

  ○ Both spacers 55 and 56 may be omitted. In this case, the sandwiching outer surfaces 52c and 53c of the sandwiching plates 52 and 53 constitute the rotor end surfaces 50a and 50b. Moreover, you may form the recessed part which accommodates the head parts 54b and 54c in the clamping outer side surfaces 52c and 53c of the clamping plates 52 and 53. FIG. Further, only one of the 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 thickness direction of the spacers 55 and 56, for example.
The configuration for connecting the plurality of electromagnetic steel plates 51 and the pair of sandwiching 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 pair of 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.

  ○ Both thrust bearings 91 and 92 were a foil type having a thrust top foil 93 and a thrust bump foil 94. However, the present invention is not limited to this, and the specific configuration thereof is arbitrary as long as it can receive a thrust force. . The same applies to both radial bearings 81 and 82.

O Either one of the 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.

  O Although the centrifugal compressor 10 of embodiment was used for some vehicle air conditioners 100, it is not restricted to this, You may use it for another use. For example, when the vehicle is a fuel cell vehicle (FCV) 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.

Next, a preferable example that can be grasped from the embodiment and another example will be described below.
(A) The centrifugal compressor according to claim 6, wherein an inner peripheral end of the thrust bearing protrudes radially inward of the rotating shaft from an inner peripheral surface of the boss.

  DESCRIPTION OF SYMBOLS 10 ... Centrifugal compressor, 11 ... Housing, 12 ... Rotary shaft, 12c ... Outer peripheral surface of rotary shaft, 13 ... Electric motor, 14, 15 ... Impeller, 30, 60 ... Suction port, 42 ... End plate (partition wall), DESCRIPTION OF SYMBOLS 50 ... Rotor, 50a ... 1st rotor end surface, 50b ... 2nd rotor end surface, 51 ... Electromagnetic steel plate, 52 ... 1st clamping plate, 53 ... 2nd clamping plate, 54 ... Rivet, 54a ... trunk | drum, 54b ... 1st Head, 54c ... second head, 55 ... first spacer, 55a ... first contact surface, 55b ... first recess (first housing portion), 56 ... second spacer, 56a ... second contact surface, 56b ... 2nd recessed part (2nd accommodating part), 61 ... Inverter (drive circuit), 62 ... Inverter case (circuit case), 71 ... 1st boss | hub, 71a ... 1st boss | hub end surface, 72 ... 2nd boss | hub, 72a ... Second boss end face, 81, 82 ... radial bearing, 83 ... Dial top foil, 84 ... Radial bump foil, 85 ... Radial gap, 91 ... First thrust bearing, 92 ... Second thrust bearing, 93 ... Thrust top foil, 94 ... Thrust bump foil, 95 ... Thrust gap, 100 ... Vehicle air conditioning Apparatus, A1, A2 ... impeller chamber, A3 ... motor chamber, A4 ... inverter chamber, A5 ... inner space.

Claims (7)

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;
With
A rotor end surface that is an end surface in the axial direction of the rotating shaft in the rotor and a boss end surface that is an end surface in the axial direction of the boss are opposed to the axial direction,
A centrifugal compressor characterized in that a thrust bearing for receiving a thrust force generated by the rotation of the impeller is provided between the rotor end surface and the boss end surface. A pair of the bosses are provided in a state of being opposed to each other in the axial direction via the rotor,
Of the pair of bosses, a first boss end surface that is the boss end surface of the first boss and a first rotor end surface of both end surfaces in the axial direction of the rotor are opposed to the axial direction,
Of the pair of bosses, the second boss end surface, which is the boss end surface of the second boss, and the second rotor end surface opposite to the first rotor end surface among the both end surfaces in the axial direction of the rotor are the axis lines. Facing the direction,
The centrifugal compressor, as the thrust bearing,
A first thrust bearing provided between the first rotor end surface and the first boss end surface;
A second thrust bearing provided between the second rotor end surface and the second boss end surface;
The centrifugal compressor according to claim 1, comprising: The rotor is
A plurality of electrical steel sheets laminated in the axial direction;
A pair of clamping plates for clamping the plurality of electromagnetic steel sheets from the axial direction;
A body portion inserted through the plurality of electromagnetic steel plates and the pair of sandwiching plates, and a diameter that is larger than that of the body portion and provided at both end portions of the body portion in the axial direction. A rivet having a head and a second head;
Of the pair of sandwiching plates, 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 A first spacer having a first housing portion in which is housed,
Of the pair of sandwiching plates, a second contact surface that contacts the plate surface of the second sandwiching plate, the second rotor end surface disposed on the opposite side of the second contact surface, and the second head A second spacer having a second housing portion in which is housed,
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. A hydrodynamic 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. A hydrodynamic 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 pair of clamping plates. The thrust bearing is
A thrust top foil that is disposed closer to the rotor end surface than the boss end surface and supports the rotor in a non-contact state when the rotary shaft rotates;
A thrust bump foil that is disposed closer to the boss end surface than the rotor end surface and elastically deforms to support the thrust top foil in a state displaceable in the axial direction;
The centrifugal compressor as described in any one of Claims 1-4 provided with these. 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, the circuit case being attached to the housing from the axial direction;
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 claim 1, wherein the drive circuit exchanges heat with a fluid in the motor chamber via the partition wall.

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