Rotor, and related electric machine, electric compressor, and electromagnetic coupling

Abstract

To provide rotors, and related electric machines, electric compressors, and electromagnetic couplings.SOLUTION: A rotor includes a thin layer (8) columnar laminate (7) including at least a first slot group (15) and a second slot group (16) arranged so as to form a first magnetic pole (P1) and a second magnetic pole (P2). The rotor further includes a magnetic flux barrier (22) arranged in each end part of each slot of the first slot group and the second slot group, two half shafts for the rotor, the rotor being a non-penetration shaft rotor, two non-magnetic and electrically insulating end disks, and a first tie rod set (100) connecting the two half shafts to keep the thin layer of laminate compacted between the two half shafts.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a permanent magnet rotor, an electromagnetic contactor, an electric machine including such a rotor, and an electric compressor including such an electric machine.

Background Art

[0002] It is known that the output density of an electric machine depends on the magnetic flux generated by the rotor and stator of the electric machine.

[0003] In the case of a permanent magnet rotor, the magnetic flux generated by the rotor is proportional to the volume of the magnets in the rotor.

[0004] It is also known that by linearly increasing the rotational speed of the rotor, the output density of the electric machine increases linearly.

[0005] It is known to arrange a plurality of permanent magnets in a rotor having a central hole and extend each permanent magnet between the central hole and the outer peripheral portion of the rotor.

[0006] The permanent magnets are regularly arranged in the rotor so that the magnetic flux is concentrated (flux concentration type rotor).

[0007] U.S. Patent Application Publication No. 2009 / 0224624 discloses a permanent magnet rotor that includes a shaft surrounding a magnetic mass that includes a multilayer of permanent magnets (multilayer rotor type).

[0008] The magnetic mass includes a laminated rotor thin layer that includes a first slot group and a second slot group arranged to form magnetic poles, and a central hole that houses the rotor shaft.

[0009] The first slot group is arranged to form magnetic flux along the direct axis of the magnetic poles resulting from the first slot group and the second slot group.

[0010] The second slot group is arranged so as to separate magnetic fluxes from adjacent magnetic poles and to be positioned along the transverse axis of the magnetic poles.

[0011] Some slots of the first slot group and the second slot group are arranged to receive permanent magnets, maximize the transverse axis inductance with respect to the direct axis inductance, and generate a reluctance torque in addition to the interaction torque generated by the magnets arranged in the stator surrounding the rotor and the current flowing into the stator, thereby maximizing the torque generated by the rotor.

[0012] In a rotor known in the prior art, since the shaft penetrates a magnetic body to accommodate the shaft, the volume of the magnet arranged in the magnetic body is limited.

[0013] Furthermore, the rotational speed of the rotor is limited so as to reduce the centrifugal force acting on the thin layer of the rotor. This is because there is a limitation due to the constraint around the central hole of the thin layer of the rotor.

[0014] Due to the constraint of the central hole, the thin layer of the rotor may be shear-deformed.

[0015] The rotational speed of the rotor is selected so that the peripheral speed of the rotor does not exceed 200 m·s -1 .

[0016] Therefore, it is proposed to completely or partially overcome these drawbacks.

Prior Art Documents

Patent Documents

[0017]

Patent Document 1

Summary of the Invention

[0018] From the above, the present invention proposes a rotor including the following. - A thin-layered cylindrical laminate including, the laminate is ○ At least a first slot group and a second slot group arranged to form a first magnetic pole, the first slot group being arranged to form a magnetic flux along the direct axis of the magnetic poles resulting from the first slot group and the second slot group, at least some of the slots of the first slot group containing a first permanent magnet, the second slot group separating the magnetic fluxes from adjacent magnetic poles and being arranged along the quadrature axis of the magnetic poles, and at least some of the slots of the second slot group containing a first permanent magnet, at least the first slot group and the second slot group, and ○ At least a second magnetic pole including, the first magnetic pole and the second magnetic pole form a pair of magnetic poles of the rotor.

[0019] The rotor further includes - Magnetic flux barriers arranged at each end of each slot of the first slot group and the second slot group, - Two half-shafts forming the shaft of the rotor and surrounding the thin laminate, the rotor being a non-through-shaft rotor, two half-shafts, - Two non-magnetic and electrically insulating end discs, each non-magnetic and electrically insulating end disc being arranged between one end of the laminate and the half-shaft, two non-magnetic and electrically insulating end discs, and - A first tie rod set connecting the two half-shafts so that the thin layers of the laminate are tightly packed between the two half-shafts, each tie rod of the first tie rod set being arranged between two adjacent slots of the first slot group or the second slot group, the first tie rod set including.

[0020] It is advantageous that at least some of the slots of the second slot group closest to the peripheral edge of the thin laminate include non-magnetic and electrically insulating blocks.

[0021] Preferably, each half shaft includes a flange that contacts a non-magnetic and electrically insulating end disk, and the rotor further includes a non-magnetic holding ring that surrounds a laminate of thin layers and a part of the flange of the half shaft. The diameter of the thin layer is shorter than the diameter of the flange. The inner surface of the holding ring contacts the outer peripheral surface of the flange, and the holding ring is made of a non-magnetic and electrically insulating material.

[0022] It is advantageous that the holding ring is made of stainless steel.

[0023] Preferably, the holding ring is made of composite fiber.

[0024] The thin layers of the laminate are separated into two sub-laminates of thin layers by at least one non-magnetic and electrically insulating intermediate disk. The diameter of the non-magnetic and electrically insulating intermediate disk is equal to the diameter of the flange, and it is advantageous that the holding ring contacts the outer peripheral surface of the non-magnetic and electrically insulating intermediate disk.

[0025] It is advantageous that the non-magnetic and electrically insulating intermediate disk is made of stainless steel.

[0026] Preferably, the non-magnetic and electrically insulating intermediate disk is made of a composite material.

[0027] Preferably, the cylindrical laminate is divided into two similar semi-cylindrical parts along the longitudinal direction of the laminate by a plane including the rotation axis of the rotor. The first magnetic pole is arranged in the first semi-cylindrical part, and the second magnetic pole is arranged in the second semi-cylindrical part. The second magnetic pole is the same as the first magnetic pole. The first slot groups and the second slot groups of the first magnetic pole and the first slot groups and the second slot groups of the second magnetic pole are symmetric with respect to the plane, and the tie rods of the first tie rod group are arranged between the first magnetic pole and the second magnetic pole.

[0028] The rotor further includes a third magnetic pole and a fourth magnetic pole similar to the first magnetic pole. The second magnetic pole is a magnetic pole similar to the first magnetic pole. The cylindrical laminate is divided into parts of four similar cylinders in the longitudinal direction of the laminate. The first magnetic pole is disposed in a part of the first cylinder, the second magnetic pole is disposed in a part of the second cylinder, the third magnetic pole is disposed in a part of the third cylinder, and the fourth magnetic pole is disposed in a part of the fourth cylinder. The first slot group and the second slot group of the first magnetic pole and the first slot group and the second slot group of the second magnetic pole are symmetric with respect to a first plane including the rotation axis of the rotor. It is advantageous that the first slot group and the second slot group of the third magnetic pole and the fourth magnetic pole and the first slot group and the second slot group of the first magnetic pole and the second magnetic pole are symmetric with respect to a second symmetric plane including the rotation axis of the rotor and perpendicular to the first plane.

[0029] Preferably, the rotor further includes a third slot group that extends along the rotation axis of the rotor and houses a second permanent magnet.

[0030] It includes a fourth slot group of slots. Each slot of the fourth slot group extends between the rotation axis of the rotor and the outer peripheral surface of the laminate, is oriented according to the first surface or the second surface, and each slot of the fourth slot group includes a third permanent magnet and a magnetic flux barrier disposed at an end portion located near the outer peripheral surface of the laminate in each slot of the fourth slot group. It is advantageous.

[0031] Preferably, the rotor further includes a second tie rod set disposed between the rotation axis of the rotor and the first magnetic pole, the second magnetic pole, the third magnetic pole, and the fourth magnetic pole and between the slots of the third slot group.

[0032] Another object of the present invention relates to an electric machine including a stator and a rotor defined as above, and the rotor is inserted into the stator.

[0033] Another object of the present invention relates to an electric compressor including the electromechanical machine and the compression part defined above, wherein the rotor is connected to the compression part.

[0034] Another object of the present invention relates to an electromagnetic coupling including the rotor and the external rotor defined above, wherein the rotor is inserted into the external rotor.

Brief Description of the Drawings

[0035] Other features and advantages of the present invention will become apparent by reading the description of embodiments of the present invention provided only as non-limiting examples below with reference to the drawings.

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Mode for Carrying Out the Invention

[0036] FIG. 1 shows an embodiment of an electric compressor 1.

[0037] The electric compressor 1 includes a compression part 2 for compressing gas and an electromechanical machine 3.

[0038] The electromechanical machine 3 includes a stator 4 and a rotor 5 inserted into the stator.

[0039] The rotor 5 includes a first permanent magnet, and the electromechanical machine 3 is a synchronous permanent magnet electric machine 3.

[0040] The rotor 5 is connected to the shaft of the compression section 2 and drives the compression section 2.

[0041] The electromechanical machine 3 may drive another mechanical system.

[0042] In a modification, the rotor 5 of the electromechanical machine 3 is driven by a motor system so that electrical energy is generated.

[0043] Figures 2 and 3 schematically show a cross-section of a first example of the rotor 5 in the longitudinal and radial directions of the rotor 5. The rotor 5 is a two-pole permanent magnet rotor.

[0044] As shown in Figure 2, the rotor 5 includes two half-shafts 6 for surrounding the columnar laminate 7 of the thin layer 8.

[0045] The two half-shafts 6 form the shaft of the rotor 5, and the rotor 5 is a non-through shaft rotor.

[0046] Each thin layer 8 represents a thin metal plate or other thin plate, and usually a plurality of thin layers are laminated and fixed to form the columnar laminate 7.

[0047] The thin layer 8 is made of a suitable ferromagnetic material (such as a material with low loss and high mechanical strength suitable for a sufficiently high rotational speed).

[0048] The rotor 5 further includes two non-magnetic and electrically insulating end discs 9, and each non-magnetic and electrically insulating end disc 9 is disposed at the end of the columnar laminate 7.

[0049] Each half-shaft 6 includes a flange 10 and a shaft 11 connected to the first surface of the flange 10.

[0050] The shaft 11 of one of the two half-shafts 6 is connected to the shaft of the compression section 2.

[0051] The second face of each flange 10 contacts one of the non-magnetic and electrically insulating end disks 9.

[0052] As will be described in detail below, the rotor 5 further includes a first slot group and a second slot group arranged in a magnetic material to form magnetic poles.

[0053] Some slots of the first slot group are provided with the first permanent magnets 12, and some slots of the second slot group are provided with the first permanent magnets 12.

[0054] Axial magnetic flux generated by the first permanent magnets is prevented from leaking to the half shaft 6 by the non-magnetic and electrically insulating end disks 9 arranged at both ends of the laminate 7.

[0055] The non-magnetic and electrically insulating end disk 9 is made of a material that can withstand the pre-stress of the thin layer 8 of the laminate 7 and has a low magnetic permeability. For example, the non-magnetic and electrically insulating end disk 9 is made of austenitic stainless steel.

[0056] The rotor 5 further includes a first tie rod set of tie rods 100. The first tie rod set of tie rods 100 connects the two half shafts 6 so that the thin layer 8 of the laminate 7 is tightly packed between the two half shafts 6, and the first set of tie rods 100 passes through the holes of the thin layer 8.

[0057] Each tie rod 100 of the first tie rod set is arranged between two adjacent slots of the first slot group or the second slot group.

[0058] The first tie rod set of tie rods 100 can be screwed or bolted to the half shaft 6.

[0059] The rotor 5 can further include a non-magnetic retaining ring 13 that surrounds the laminate 7 of the thin layer 8 and partially surrounds the flange 10 of the half shaft 6.

[0060] The diameter of the thin layer 8 is smaller than the diameter of the flange 10 such that the inner surface of the retaining ring 13 contacts the outer peripheral surface of the flange 10.

[0061] The retaining ring 13 is made of a non-magnetic and electrically insulating material (e.g., stainless steel or composite fiber (such as thermoplastic carbon fiber)).

[0062] The retaining ring 13 holds the thin layer 8 and the magnet from being pushed out of the rotor 5 by the action of centrifugal force.

[0063] The rotor 5 including the half shaft 6 and the retaining ring 13 rotates at a rotational speed such that the peripheral speed of the rotor 5 exceeds 200 m·s -1 and the power density of the rotor 5 can be increased as compared with a permanent magnet rotor known from the prior art.

[0064] Furthermore, since the diameter of the thin layer 8 is smaller than the inner diameter of the retaining ring 13, the retaining ring 9 can apply a pre-stress to the laminate 7 of the thin layer 8.

[0065] The laminate 7 can further include at least one intermediate non-magnetic and electrically insulating intermediate disk 14 for separating the laminate 7 into two sub-laminates of the thin layer 8.

[0066] As shown in the figure, the laminate 7 includes two non-magnetic and electrically insulating intermediate disks 14 arranged in the laminate 7, the thin layer 8 is divided into three sub-laminates having the same length Ls, and the sum of the lengths Ls of the three sub-laminates is equal to the length Lt of the laminate 7.

[0067] In a modified example, the lengths of the respective sub-laminates may be different, and the sum of the lengths of the sub-laminates is equal to the length Lt of the laminate 7.

[0068] Each intermediate disk 14 that is non-magnetic and electrically insulating can be made of a non-magnetic and electrically insulating material (e.g., stainless steel or composite material (such as thermoplastic carbon fiber)).

[0069] The laminate 7 may include three or more nonmagnetic and electrically insulating intermediate disks 14.

[0070] The diameter of the nonmagnetic and electrically insulating intermediate disk 14 is equal to the diameter of the flange 10, and the holding ring 13 contacts the outer peripheral surface of the nonmagnetic and electrically insulating intermediate disk 14.

[0071] The nonmagnetic and electrically insulating intermediate disk 14 homogenizes the pre-stress applied by the first tie rod set to the thin layer 8 and is made of, for example, nonmagnetic stainless steel.

[0072] As shown in FIG. 3, the cylindrical laminate is divided in the longitudinal direction into two similar semi-cylindrical portions C1 and C2 by a plane PL1 including the rotation axis A.

[0073] The first magnetic pole P1 is arranged in the first semi-cylindrical portion C1, and a second magnetic pole P2 similar to the first magnetic pole P1 is arranged in the second semi-cylindrical portion C2.

[0074] Each of the magnetic poles P1 and P2 includes a first slot group 15, 15a provided with a first permanent magnet 12 and a second slot group 16, 16a provided with a first permanent magnet 12, respectively.

[0075] Since the two magnetic poles P1 and P2 are similar, the first magnetic pole P1 will be described in detail below.

[0076] The first slot group 15 is arranged so as to form a magnetic flux along the direct axis P of the first magnetic pole P1 generated by the first slot group 15 and the second slot group 16.

[0077] The second slot group 16 separates the magnetic flux from the adjacent magnetic poles and is arranged along the transverse axis Q of the first magnetic pole P1.

[0078] The slots of the second slot group 16 are arranged on both sides of the slots of the first slot group 15.

[0079] The direct axis P is the axis on which magnetic flux is generated by the magnets 14 of the first slot group 15.

[0080] Since the rotor 5 is a two-pole permanent magnet rotor, the quadrature axis Q is the axis located at a right angle to the direct axis P. The quadrature axis Q is angularly located at the center between two adjacent magnetic poles P1 and P2.

[0081] The angle between the direct axis P and the quadrature axis Q is equal to the value obtained by dividing 180° by the number of magnetic poles. The number of magnetic poles is even, and the magnetic poles form pairs of magnetic poles.

[0082] For example, in a two-pole rotor (such as the rotor 5) forming a pair of magnetic poles, the angle between the direct axis P and the quadrature axis Q is equal to 90°. In a four-pole rotor, the angle between the direct axis P and the quadrature axis Q is equal to 45°. In a six-pole rotor, the angle between the direct axis P and the quadrature axis Q is equal to 30°.

[0083] The slots of the first slot group 15 are arranged perpendicular to the direct axis P.

[0084] At least some of the slots of the first slot group are arranged to accommodate the respective first permanent magnets 14. As shown in the figure, each slot of the first slot group 15 includes the first permanent magnet 14.

[0085] The slots of the first slot group 15 can be overlapped with each other along the direct axis P in the order of decreasing length in the direction perpendicular to the direct axis P of the slots of the first slot group 15. Among the slots of the first slot group 15, the slot with the longest length in the direction perpendicular to the direct axis P is closest to the rotation axis A, and among the slots of the first slot group 15, the slot with the shortest length in the direction perpendicular to the direct axis P is closest to the peripheral edge of the thin layer 8.

[0086] At least some of the slots of the second slot group 16 can be arranged to each include a respective first permanent magnet 12. In one example embodiment, as shown in FIG. 3, each slot of the second slot group 16 includes a first permanent magnet 12. This arrangement maximizes the magnetic field generated by the magnetic poles P1, P2.

[0087] At least some of the slots of the second slot group 16 extend from respective transfer posts (e.g., transfer post 18) configured to mechanically transfer from the first slot group 15 to the second slot group 16. That is, each transfer post provides a structural member between one slot of the first slot group 15 and an adjacent slot of the second slot group 16 to withstand the expected mechanical forces.

[0088] Each slot of the second slot group 16 that extends from a respective transfer post is arranged in the path of the magnetic flux along the horizontal axis Q and can include a portion that extends obliquely with respect to the radius passing through the corresponding opening for accommodating the tie rod of the first tie rod set.

[0089] The slots of the second slot group 16 can be composed of a pair of slots (such as slot pairs 19 and 20 extending from respective central posts 21).

[0090] At each end of each slot of the first slot group 15 and the second slot group 16, a magnetic flux barrier 22 is arranged to prevent the axial magnetic flux generated by the first permanent magnet 12 from forming a loop in the thin layer 7, and thus maximize the magnetic flux that generates torque on the shaft 11 of the half shaft 6.

[0091] The magnetic flux barrier 22 may be air or a non-magnetic and electrically insulating wedge inserted at the end of the slot.

[0092] The first slot group 15 and the second slot group 16 of the first magnetic pole P1 and the first slot group 15a and the second slot group 16a of the second magnetic pole P2 are symmetric with respect to the plane PL1.

[0093] Some tie rods 100 of the first tie rod group are arranged between the first magnetic pole P1 and the second magnetic pole P2.

[0094] Since the rotor 5 includes a non-through rotor shaft composed of two half shafts 6, the thin layer 8 does not include a central hole for accommodating the through rotor shaft, and the first slot group 15 and the second slot group 16 include more slots than the permanent magnets known from the prior art without changing the dimensions of the rotor.

[0095] Since the volume of the first permanent magnet 12 arranged in the first slot group 15 and the second slot group 16 of the magnetic poles P1, P2 increases, the magnetic flux supplied from the rotor 5 increases compared with the permanent magnet rotor known from the prior art, thereby increasing the torque transmitted by the electric machine 3 to the shaft 11 of the half shaft 6.

[0096] Since the torque supplied by the machine 3 increases without changing the size (encumbrance) of the machine 2, the output density of the machine 3 increases compared with the permanent magnet machines known in the prior art.

[0097] The first permanent magnet 12 and the wedge inserted into the end of the slot can be firmly coupled to the thin layer 8 in order to prevent the first permanent magnet 12 from moving within the slot under the influence of centrifugal force.

[0098] The first permanent magnet 12 and the wedge are adhered, for example, within the slot.

[0099] The thickness of the retaining ring 13 is selected to be as thick as possible so that the amplitude of the magnetic induction in the air gap of the machine 3 generated by the first permanent magnet embedded in the laminate 7 increases.

[0100] Furthermore, when the thickness of the retaining ring 13 is reduced, the rotor 5 includes more permanent magnets 12 as compared to a rotor known from the prior art having the same dimensions as the rotor 5.

[0101] FIG. 4 schematically shows a cross section of a second example of the rotor 5 in the radial direction of the rotor 5.

[0102] The second example of the rotor 5 is different from the first example of the rotor 5 shown in FIGS. 2 and 3 in that, at the first and second magnetic poles P1, P2, the slot 21 of the second slot group closest to the outer peripheral portion of the thin-layer laminate includes a non-magnetic and electrically insulating block 23 instead of the first permanent magnet 12.

[0103] Some of the slots 24 of the second slot group 16 of the first and second magnetic poles P1, P2 can include the first permanent magnet 12 and a non-magnetic and electrically insulating block 23.

[0104] In a variant, some of the slots of the second slot group of the first and second magnetic poles P1, P2 include a block 23 instead of the first permanent magnet 12.

[0105] By replacing all or part of the first permanent magnets 12 in some of the slots of the second slot group 16 of the first and second magnetic poles P1, P2, the number of the first permanent magnets 12 in the rotor 5 can be reduced while maintaining the salient pole effect.

[0106] In the second slot group 16, the number of the first permanent magnets 12 replaced by the blocks 23 is determined such that the magnetic flux generated by the first permanent magnets 12 of the rotor 5 is sufficient to drive a mechanical system (e.g., the compression part 2) connected to one of the half-shafts of the half-shaft, or is sufficient to generate the electrical energy required when the rotor 5 is driven by a motor system.

[0107] The block 23 inserted into the slots of the second slot group 16 can be firmly coupled to the thin layer 8 in order to prevent the block 23 from moving within the slot under the influence of centrifugal force.

[0108] The block 23 is, for example, adhered to the slot.

[0109] FIG. 5 schematically shows a cross-section of a third example of the rotor 5 in the radial direction of the rotor 5.

[0110] The rotor 5 includes first and second magnetic poles P1, P2 including first and second slot groups, and third and fourth magnetic poles P3, P4 similar to the first and second poles P1, P2.

[0111] The machine 3 including the rotor 5 is a four-pole permanent magnet synchronous machine.

[0112] The cylindrical laminate 7 is divided along the longitudinal direction of the laminate 7 into parts C10, C11, C12, C13 of four similar cylinders.

[0113] The first magnetic pole P1 is arranged in a part C10 of the first cylinder, the second magnetic pole P2 is arranged in a part C11 of the second cylinder, the third magnetic pole P3 is arranged in a part C13 of the third cylinder, and the fourth magnetic pole P4 is arranged in a part C14 of the fourth cylinder.

[0114] The magnetic poles P1, P2, P3, P4 are arranged in parts C10, C11, C12, 13 of the cylinder. The first slot group 15 and the second slot group 16 of the first magnetic pole P1, and the first slot group 15a and the second slot group 16a of the second magnetic pole P2 are symmetric with respect to a first plane PL10 including the rotation axis A of the rotor 5. The first and second slot groups 15b, 15c, 16b, 16c of the third magnetic pole P3 and the fourth magnetic pole P4, and the first and second slot groups 15, 15a, 16, 16a of the first magnetic pole P1 and the second magnetic pole P2 are symmetric with respect to a second symmetric plane PL20 including the rotation axis A and perpendicular to the first plane PL10.

[0115] The slots of the first and second slot groups 15, 15a, 15b, 15c, 16, 16a, 16b, 16c of the magnetic poles P1, P2, P3, P4 contain the permanent magnet 12.

[0116] The rotor 5 can further include a third slot group 25 that extends along the rotation axis A of the rotor 5 and houses a rod 26 made of a non-magnetic and electrically insulating material (e.g., stainless steel or a composite material such as thermoplastic carbon fiber). The rod 26 and the slot 25 can be cylindrical.

[0117] The rotor 5 can further include a fourth slot group of slots 27a, 27b, 27c, 27d.

[0118] Each slot 27a, 27b, 27c, 27d of the fourth slot group extends between the rotation axis A of the rotor 5 and the outer peripheral surface of the laminate 7.

[0119] The first slot 27a and the second slot 27b of the fourth slot group are oriented according to a first plane P10, and the third slot 27c and the fourth slot 27d of the fourth slot group are oriented according to a second plane P20.

[0120] The first slot 27a of the fourth slot group is disposed between the first magnetic pole P1 and the second magnetic pole P2, the second slot 27b of the fourth slot group is disposed between the third magnetic pole P3 and the fourth magnetic pole P4, the third slot 27c of the fourth slot group is disposed between the second magnetic pole P2 and the third magnetic pole P3, and the fourth slot 27d of the fourth slot group is disposed between the first magnetic pole P1 and the fourth magnetic pole P4.

[0121] The slots 27a, 27b, 27c, 27d of the fourth slot group include a third permanent magnet 28 and a magnetic flux barrier 29 disposed at an end near the outer peripheral surface of the laminate 7 in the slots 27a, 27b, 27c, 27d.

[0122] The rod 26 and the slot 25 can be cylindrical. The rod 26 prevents the leakage of magnetic flux generated by the third permanent magnet.

[0123] The rotor 5 including the first and second slot groups 15, 15a, 15b, 15c, 16, 16a, 16b, 16c of the magnetic poles P1, P2, P3, P4 including the permanent magnet 12 and the fourth slot group of the slots 27a, 27b, 27c, 27d including the third permanent magnet 28 and the magnetic flux barrier 29 forms a rotor that combines a multi-layer rotor type known in the prior art and a magnetic flux concentration type known in the prior art. The rotor 5 contains more permanent magnets than a rotor known in the prior art.

[0124] Since the torque density of the machine 3 is proportional to the magnetic flux generated by the magnets of the rotor 5, the torque density of the machine 3 increases compared to a machine known from the prior art having the same load as the machine 3.

[0125] The third permanent magnet 28 adds the field alignment torque on the direct axis of each of the magnetic poles P1, P2, P3, P4 and the reluctance torque on the quadrature axis of each of the magnetic poles P1, P2, P3, P4, maximizing the amount of torque generated by the rotor 5.

[0126] The second and third permanent magnets 26, 28 inserted into the ends of the slots can be firmly coupled to the thin layer 8 so that the second and third permanent magnets 26, 28 are prevented from moving within the slots due to the influence of centrifugal force.

[0127] The second and third permanent magnets 26, 28 are, for example, adhered to the slots.

[0128] The laminate 7 further includes a second tie rod set of tie rods 30 arranged between the rotation axis A of the rotor and the first, second, third, and fourth magnetic poles P1, P2, P3, P4 and between the slots of the fourth slot group of the slots 27a, 27b, 27c, 27d.

[0129] The tie rod 30 of the second tie rod set couples two non-magnetic and electrically insulating end discs 9 so that the thin layer 8 of the laminate 7 is tightly packed between the non-magnetic and electrically insulating end disc 9 and the through holes of the thin layer 8.

[0130] The tie rod 30 of the second tie rod set can be screwed or bolted to the non-magnetic and electrically insulating end disc 9.

[0131] In a modification, the rotor 5 may include more than four poles. Accordingly, the cylindrical laminate 7 is divided, and the number of poles is even. The cylindrical laminate 7 is divided into a plurality of parts of the same cylinder in the longitudinal direction of the laminate 7. The number of parts of the cylinder is equal to the number of poles, and each pole is arranged in a part of the cylinder. The first slot group and the second slot group of one pole and the first slot group and the second slot group of the adjacent pole are symmetric with respect to a plane including the rotation axis A of the rotor 5, that is, a plane separating a part of the cylinder of one pole from a part of the cylinder of the adjacent pole.

[0132] FIG. 6 shows an example of the electromagnetic coupling 40. The electromagnetic coupling 40 includes an outer rotor 41. The rotor 5 is inserted into the outer rotor 41. The torque applied to one of the rotor 5 and the outer rotor 41 is transmitted to the other rotor through the air gap.

Explanation of Reference Numerals

[0133] 1 Electric compressor 3 Electromechanical 4 Stator 5 Rotor 6 Half shaft 10 Flange 11 Shaft 22 Magnetic flux barrier 23 Block 24 Slot 29 Magnetic flux barrier 30 Tie rod 40 Electromagnetic coupling 41 Outer rotor 100 Tie rod

Claims

1. A rotor (5), comprising: - A columnar laminate (7) of thin layers (8), wherein the laminate (7) includes: ○ At least a first slot group (15) and a second slot group (16) arranged to form a first magnetic pole (P1), the first slot group (15) being arranged to form a magnetic flux along the direct axis (P) of the magnetic poles resulting from the first and second slot groups, at least some slots of the first slot group including a first permanent magnet (12), the second slot group being arranged to separate the magnetic fluxes from adjacent magnetic poles and along the quadrature axis (Q) of the magnetic poles, and at least some slots of the second slot group including a first permanent magnet; at least the first slot group (15) and the second slot group (16), and ○ At least a second magnetic pole (P2), wherein the first magnetic pole (P1) and the second magnetic pole (P2) form a pair of magnetic poles of the rotor; The rotor further includes: - A magnetic flux barrier (22) arranged at each end of each slot of the first and second slot groups; - Two half-shafts (6) forming the shaft of the rotor and surrounding the laminate of thin layers, the rotor being a non-through-shaft rotor; - Two non-magnetic and electrically insulating end discs (9), each non-magnetic and electrically insulating end disc being arranged between one end of the laminate and the half-shaft; two non-magnetic and electrically insulating end discs (9), and - A first tie rod set (100) connecting the two half-shafts so as to tightly pack the thin layers of the laminate between the two half-shafts, each tie rod of the first tie rod set being arranged between two adjacent slots of the first or second slot group; the first tie rod set (100). A rotor comprising the above.

2. The rotor according to claim 1, wherein at least some slots of the second slot group (16) closest to the peripheral edge of the laminate (7) of the thin layer (8) include a non-magnetic and electrically insulating block (23).

3. Each half - shaft (6) includes a flange (10) that contacts a non - magnetic and electrically insulating end - disk (9). The rotor further includes a non - magnetic holding ring (13) that surrounds a laminate (7) of thin layers (8) and a part of the flange of the half - shaft. The diameter of the thin layer (8) is shorter than the diameter of the flange. The inner surface of the holding ring (13) contacts the outer peripheral surface of the flange, and the holding ring is made of a non - magnetic and electrically insulating material. The rotor according to claim 1 or 2.

4. The rotor according to claim 3, wherein the holding ring (13) is made of stainless steel.

5. The rotor according to claim 3, wherein the holding ring (13) is made of composite fiber.

6. The thin layer (8) of the laminate (7) is separated into two sub - laminates of the thin layer by at least one non - magnetic and electrically insulating intermediate disk (14). The diameter of the non - magnetic and electrically insulating intermediate disk is equal to the diameter of the flange (10). The holding ring contacts the outer peripheral surface of the non - magnetic and electrically insulating intermediate disk. The rotor according to any one of claims 3 to 5.

7. The cylindrical laminate (7) is divided into two similar semi - cylindrical parts (C1, C2) along the longitudinal direction of the laminate by a plane (PL1) including the rotation axis (A) of the rotor. The first magnetic pole (P1) is arranged in the first semi - cylindrical part (C1), and the second magnetic pole (P2) is arranged in the second semi - cylindrical part (C2). The second magnetic pole is similar to the first magnetic pole. The first slot groups and the second slot groups (15, 16) of the first magnetic pole (P1) and the first slot groups and the second slot groups (15a, 16a) of the second magnetic pole (P2) are symmetric with respect to the plane (PL1). Tie - rods of the first tie - rod group (100) are arranged between the first magnetic pole and the second magnetic pole. The rotor according to any one of claims 1 to 6.

8. Further includes a third magnetic pole (P3) and a fourth magnetic pole (P3) similar to the first magnetic pole (P1), the second magnetic pole (P2) is a magnetic pole similar to the first magnetic pole (P1), the cylindrical laminate (7) is divided into parts (C10, C11, C12, C13) of four similar cylinders in the longitudinal direction of the laminate, the first magnetic pole (P1) is arranged in a part (C10) of the first cylinder, the second magnetic pole (P2) is arranged in a part (C11) of the second cylinder, the third magnetic pole (P3) is arranged in a part (C12) of the third cylinder, the fourth magnetic pole (P4) is arranged in a part (C13) of the fourth cylinder, the first slot group and the second slot group (15, 16) of the first magnetic pole (P1) and the first slot group and the second slot group (15a, 16a) of the second magnetic pole (P2) are symmetric with respect to a first plane (PL10) including the rotation axis (A) of the rotor, and the first slot group and the second slot group (15b, 15c, 16b, 16c) of the third magnetic pole and the fourth magnetic pole (P3, P4) and the first slot group and the second slot group of the first magnetic pole and the second magnetic pole are symmetric with respect to a second symmetric plane (PL20) including the rotation axis (A) of the rotor and perpendicular to the first plane. The rotor according to any one of claims 1 to 6.

9. The rotor according to claim 8, further including a third slot group (25) that extends along the rotation axis (A) of the rotor (5) and houses a second permanent magnet (26).

10. Further includes a fourth slot group of slots (27a, 27b, 27c, 27d), each slot of the fourth slot group extends between the rotation axis (A) of the rotor and the outer peripheral surface of the laminate (7), is oriented according to the first surface or the second surface (PL10, PL20), and each slot of the fourth slot group includes a third permanent magnet (28) and a magnetic flux barrier (29) arranged at an end portion located near the outer peripheral surface of the laminate in each slot of the fourth slot group. The rotor according to claim 8 or 9.

11. The rotor according to claim 10, further including a second tie rod set (30) arranged between the rotation axis of the rotor and the first magnetic pole, the second magnetic pole, the third magnetic pole, and the fourth magnetic pole, and between the slots of the fourth slot group (27a, 27b, 27c, 27d).

12. An electric machine (3) comprising a stator (4) and a rotor (5) according to any one of claims 1 to 11, wherein the rotor is inserted into the stator.

13. An electric compressor (1) comprising the electric machine (3) according to claim 12 and a compression part (2), wherein the rotor is connected to the compression part.

14. An electromagnetic contactor (40) comprising a rotor (5) according to any one of claims 1 to 11 and an external rotor (41), wherein the rotor is inserted into the external rotor.

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