Rotor and associated electric machine, motor compressor and magnetic coupling

Abstract

The invention relates to a rotor comprising a cylindrical stack (7) of laminations (8), the cylindrical stack (7) comprising at least a first (15) and a second (16) group of slots arranged to form a first pole (P1) and a second pole (P2). The rotor further comprises:-a magnetic flux barrier (22) arranged at each end of each slot of the first and second sets of slots,-two half shafts enclosing the stack of laminations and forming the shaft of the rotor, the rotor being a non-through-shaft rotor,-two non-magnetic and electrically insulating end discs, each end disc having a magnetic flux barrier (22) arranged at each end of each slot of the first and second sets of slots,-two semi-shafts enclosing the stack of laminations and forming the shaft of the rotor, the rotor being a non-through-shaft rotor, and-a magnetic flux barrier (22) arranged at each end of each slot of the first and second sets of slots. The invention relates to a stack comprising:-a plurality of end discs (100), each end disc being interposed between one end of the stack and the half-shafts, and-a first set of tie rods (100) connecting the two half-shafts so as to keep the laminations of the stack compacted between the two half-shafts, each tie rod of the first set of tie rods being arranged between two adjacent slots of the first or second set of slots.

Description

TECHNICAL FIELD

[0001] The present invention relates to a permanent magnet rotor, a magnetic coupler, an electric motor including such a rotor, and a motor compressor including such an electric motor. BACKGROUND ART

[0002] The power density of a known electric motor depends on the magnetic flux generated by the rotor and stator of the electric motor.

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

[0004] It is also known that the power density of an electric motor increases linearly by linearly increasing the rotational speed of the rotor.

[0005] It is known to arrange permanent magnets in a rotor including a central hole such that each permanent magnet extends between the central hole and the periphery of the rotor.

[0006] The permanent magnets are regularly arranged in the rotor to concentrate the magnetic flux (flux concentrating rotor type).

[0007] Document US2009 / 0224624 discloses a permanent magnet rotor including a shaft enclosing a magnetic mass including multiple layers of permanent magnets (multiple layer rotor type).

[0008] The magnetic mass includes stacked rotor laminations including a first set of slots and a second set of slots arranged to form poles, and a central hole for receiving the rotor shaft.

[0009] The first set of slots is arranged to form a magnetic flux along the direct axis of the poles generated by the first set of slots and the second set of slots.

[0010] The second set of slots is arranged to provide separation of the magnetic flux from adjacent poles and is disposed along the interaxis of the poles.

[0011] Some of the first set of slots and the second set of slots are arranged to receive permanent magnets to maximize the quadrature inductance relative to the direct inductance, thereby resulting in the formation of a reluctance torque exceeding the interaction torque generated by the magnets and the current injected into the stator surrounding the rotor, so as to maximize the torque generated by the rotor.

[0012] In the rotors known from the prior art, when the shaft passes through the magnetic mass to accommodate the shaft, the volume of the magnets arranged in the magnetic mass is limited.

[0013] In addition, the rotational speed of the rotor is limited to reduce the centrifugal force acting on the rotor laminations in order to limit the constraint on the periphery of the central hole of the rotor laminations.

[0014] The constraint on the central hole can shear the rotor laminations.

[0015] The rotational speed of the rotor can be selected such 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. Summary of the Invention

[0017] In view of the foregoing, the present invention proposes a rotor, which comprises: - A cylindrical stack of laminations, which comprises: ○ At least a first set of slots and a second set of slots, the first set of slots and the second set of slots are arranged to form a first pole, the first set of slots are arranged to form a magnetic flux along the straight axis of the pole generated by the first set of slots and the second set of slots, at least some of the first set of slots include first permanent magnets, the second set of slots are arranged to provide a separation of the magnetic flux from adjacent poles, and are arranged along the intersection axis of the poles, at least some of the second set of slots include first permanent magnets, and ○ At least a second pole, the first pole and the second pole form a pair of poles of the rotor.

[0018] The rotor further comprises: - A magnetic flux barrier, which is arranged at each end of each slot in the first set of slots and the second set of slots, - Two half shafts, which enclose the stack of laminations and form the shaft of the rotor, and the rotor is a non-through shaft rotor, - Two non-magnetic and electrically insulating end discs, each non-magnetic and electrically insulating end disc is inserted between one end of the stack and the half shaft, and - A first set of tie rods, which connect the two half shafts to keep the laminations of the stack compacted between the two half shafts, and each tie rod in the first set of tie rods is arranged between two adjacent slots in the first set of slots or the second set of slots.

[0019] Advantageously, at least some of the slots in the second set of slots closest to the periphery of the stack of laminations include non-magnetic and electrically insulating blocks.

[0020] Preferably, each half shaft includes a flange in contact with the non-magnetic and electrically insulating end disc, the rotor further comprises a non-magnetic retaining ring, the non-magnetic retaining ring encloses the stack of laminations and partially encloses the flange of the half shaft, the diameter of the laminations is smaller than the diameter of the flange, such that the inner surface of the retaining ring is in contact with the peripheral surface of the flange, and the retaining ring is made of non-magnetic and electrically insulating material.

[0021] Advantageously, the retaining ring is made of stainless steel.

[0022] Preferably, the retaining ring is made of composite fiber.

[0023] Advantageously, the stacked laminations are separated into two sub-stacks of laminations by at least one intermediate non-magnetic and electrically insulating disc, the diameter of the intermediate non-magnetic and electrically insulating disc being equal to the diameter of the flange, such that the retaining ring is in contact with the peripheral surface of the intermediate non-magnetic and electrically insulating disc.

[0024] Advantageously, the intermediate non-magnetic and electrically insulating disc is made of stainless steel.

[0025] Preferably, the intermediate non-magnetic and electrically insulating disc is made of a composite material.

[0026] Preferably, the cylindrical stack is divided into two similar semi-cylinders in the longitudinal direction of the stack by a plane including the rotational axis of the rotor, a first pole being arranged in the first semi-cylinder, a second pole being arranged in the second semi-cylinder and being similar to the first pole, the first set of slots and the second set of slots of the first pole being symmetric with respect to the first set of slots and the second set of slots of the second pole with respect to this plane, the tie rods in the first set of tie rods being arranged between the first pole and the second pole.

[0027] Advantageously, the rotor includes a third pole and a fourth pole similar to the first pole, the second pole being similar to the first pole, wherein the cylindrical stack is divided into four similar cylindrical parts in the longitudinal direction of the stack, the first pole being arranged in the first cylindrical part, the second pole being arranged in the second cylindrical part, the third pole being arranged in the third cylindrical part, the fourth pole being arranged in the fourth cylindrical part, such that the first set of slots and the second set of slots of the first pole are symmetric with respect to a first plane including the rotational axis of the rotor with respect to the first set of slots and the second set of slots of the second pole, and the first set of slots and the second set of slots of the third pole and the fourth pole are symmetric with respect to a second plane of symmetry including the rotational axis of the rotor and perpendicular to the first plane with respect to the first set of slots and the second set of slots of the first pole and the second pole.

[0028] Preferably, the rotor further includes a third set of slots extending along the rotational axis of the rotor and accommodating a second permanent magnet.

[0029] Advantageously, the rotor includes a fourth set of slots, each slot in the fourth set of slots extending between the rotational axis of the rotor and the peripheral surface of the stack and being oriented according to the first plane or the second plane, each slot in the fourth set of slots including a third permanent magnet and a magnetic flux barrier arranged at an end of each slot in the fourth set of slots close to the peripheral surface of the stack.

[0030] Preferably, the rotor further includes a second set of tie rods arranged between the rotational axis of the rotor and the first pole, the second pole, the third pole and the fourth pole, and between the slots in the third set of slots.

[0031] Another object of the present invention relates to an electric machine including a stator and a rotor as defined above, the rotor being inserted into the stator.

[0032] Another object of the present invention relates to a motor compressor, which comprises an electric motor and a compression section as defined above, and a rotor is connected to the compression section.

[0033] Another object of the present invention relates to a magnetic coupler, which comprises a rotor and an outer rotor as defined above, and the rotor is inserted into the outer rotor.

[0034] This application may also include the following solutions: Solution 1. A rotor, comprising: - A laminated cylindrical stack, the cylindrical stack comprising: ○ At least a first set of slots and a second set of slots, the first set of slots and the second set of slots are arranged to form a first pole, the first set of slots are arranged to form a magnetic flux along the straight axis of the pole generated by the first set of slots and the second set of slots, at least some of the first set of slots include a first permanent magnet, the second set of slots are arranged to provide a separation of the magnetic flux from an adjacent pole, and are arranged along the intersection axis of the poles, and at least some of the second set of slots include a first permanent magnet, and ○ At least a second pole, the first pole and the second pole form a pair of poles of the rotor, characterized in that the rotor further comprises: - A magnetic flux barrier, the magnetic flux barrier is arranged at each end of each slot in the first set of slots and the second set of slots, - Two half shafts, the two half shafts enclose the stack of laminations and form the shaft of the rotor, and the rotor is a non-through shaft rotor, - Two non-magnetic and electrically insulating end plates, each non-magnetic and electrically insulating end plate is inserted between one end of the stack and the half shaft, and - A first set of tie rods, the first set of tie rods connect the two half shafts to keep the laminations of the stack compacted between the two half shafts, and each tie rod in the first set of tie rods is arranged between two adjacent slots in the first set of slots or the second set of slots.

[0035] Solution 2. The rotor according to Solution 1, wherein at least some of the slots in the second set of slots closest to the periphery of the stack of laminations include non-magnetic and electrically insulating blocks.

[0036] Solution 3. The rotor according to Solution 1 or 2, wherein each half shaft includes a flange in contact with the non-magnetic and electrically insulating end plate, the rotor further includes a non-magnetic retaining ring, the non-magnetic retaining ring encloses the stack of laminations and partially encloses the flange of the half shaft, the diameter of the stack of laminations is smaller than the diameter of the flange, so that the inner surface of the retaining ring contacts the peripheral surface of the flange, and the retaining ring is made of non-magnetic and electrically insulating material.

[0037] Solution 4. The rotor according to Solution 3, wherein the retaining ring is made of stainless steel.

[0038] Solution 5. The rotor according to Solution 3, wherein the retaining ring is made of composite fiber.

[0039] Solution 6. The rotor according to any one of Solutions 3 to 5, wherein the laminations of the stack are separated into two sub-stacks of laminations by at least one intermediate non-magnetic and electrically insulating disc, the diameter of the intermediate non-magnetic and electrically insulating disc being equal to the diameter of the flange such that the retaining ring contacts the peripheral surface of the intermediate non-magnetic and electrically insulating disc.

[0040] Solution 7. The rotor according to any one of Solutions 1 to 6, wherein the cylindrical stack is divided in the longitudinal direction of the stack into two similar semi-cylinders by a plane including the axis of rotation of the rotor, the first pole being arranged in the first semi-cylinder, the second pole being arranged in the second semi-cylinder and being similar to the first pole, the first set of slots and the second set of slots of the first pole being symmetric with respect to the plane to the first set of slots and the second set of slots of the second pole, and the tie rods in the first set of tie rods being arranged between the first pole and the second pole.

[0041] Solution 8. The rotor according to any one of Solutions 1 to 6, further comprising a third pole and a fourth pole similar to the first pole, the second pole being similar to the first pole, wherein the cylindrical stack is divided in the longitudinal direction of the stack into four similar cylindrical parts, the first pole being arranged in the first cylindrical part, the second pole being arranged in the second cylindrical part, the third pole being arranged in the third cylindrical part, the fourth pole being arranged in the fourth cylindrical part such that the first set of slots and the second set of slots of the first pole are symmetric with respect to a first plane including the axis of rotation of the rotor to the first set of slots and the second set of slots of the second pole, and the first set of slots and the second set of slots of the third pole and the fourth pole are symmetric with respect to a second plane of symmetry including the axis of rotation of the rotor and perpendicular to the first plane to the first set of slots and the second set of slots of the first pole and the second pole.

[0042] Solution 9. The rotor according to Solution 8, further comprising a third set of slots extending along the axis of rotation of the rotor and accommodating a second permanent magnet.

[0043] Solution 10. The rotor according to Solution 8 or 9 further includes a fourth set of slots, each slot in the fourth set of slots extending between the rotational axis of the rotor and the peripheral surface of the stack and being oriented according to the first plane or the second plane, each slot in the fourth set of slots including a third permanent magnet and a magnetic flux barrier disposed at the end of each slot in the fourth set of slots near the peripheral surface of the stack.

[0044] Solution 11. The rotor according to Solution 10 further includes a second set of tie rods, the second set of tie rods being disposed between the rotational axis of the rotor and the first pole, the second pole, the third pole, and the fourth pole, and between the slots in the fourth set of slots.

[0045] Solution 12. An electric machine including a stator and a rotor according to any one of Solutions 1 to 11, the rotor being inserted into the stator.

[0046] Solution 13. A motor compressor including the electric machine according to Solution 12 and a compression section, the rotor being connected to the compression section.

[0047] Solution 14. A magnetic coupler including a rotor according to any one of Solutions 1 to 11 and an outer rotor, the rotor being inserted into the outer rotor. Description of the Drawings

[0048] Other features and advantages of the present invention will become apparent upon reading the following description of embodiments of the present invention, which are provided by way of non-limiting example only and with reference to the drawings, in which:

[0049] Figure 1 Illustrates an embodiment of a motor compressor according to the present invention,

[0050] Figure 2 and Figure 3 Schematically illustrates a first example of a rotor according to the present invention,

[0051] Figure 4 Schematically illustrates a second example of a rotor according to the present invention,

[0052] Figure 5 Schematically illustrates a third example of a rotor according to the present invention, and

[0053] Figure 6 Schematically illustrates an example of a magnetic coupler according to the present invention. Detailed Description

[0054] Figure 1 Illustrates an embodiment of the motor compressor 1.

[0055] The motor compressor 1 includes a compression section 2 intended to compress a gas and an electric motor 3.

[0056] The electric motor 3 includes a stator 4 and a rotor 5 received in the stator.

[0057] The rotor 5 includes a first permanent magnet, and the electric motor 3 is a synchronous permanent magnet electric motor 3.

[0058] The rotor 5 is connected to the shaft of the compression section 2 to drive the compression section 2.

[0059] The electric motor 3 can drive another mechanical system.

[0060] In a variant, the rotor 5 of the electric motor 3 is driven by a motor system to generate electrical energy.

[0061] Figure 2 and Figure 3 Schematically illustrates a cross-section of a first example of the rotor 5 with respect to the longitudinal direction and the radial direction of the rotor 5, and the rotor 5 is a two-pole permanent magnet rotor.

[0062] As illustrated in Figure 2 The rotor 5 includes two half-shafts 6 enclosing a cylindrical stack 7 of laminations 8.

[0063] The two half-shafts 6 form the shaft of the rotor 5, and the rotor 5 is a non-through-shaft rotor.

[0064] Each lamination 8 refers to a thin metal sheet or other thin sheet, and a plurality of them are typically stacked and bonded together to form the cylindrical stack 7.

[0065] The laminations 8 are made of a suitable ferromagnetic material, such as a material that may have low losses and high mechanical strength suitable for significantly high rotational speeds.

[0066] The rotor 5 further includes two non-magnetic and electrically insulating end plates 9, and each non-magnetic and electrically insulating end plate 9 is arranged at the end of the cylindrical stack 7.

[0067] Each half-shaft 6 includes a flange 10 and a shaft 11 connected to the first face of the flange 10.

[0068] The shaft 11 of one of the half-shafts 6 is connected to the shaft of the compression section 2.

[0069] The second face of each flange 10 is in contact with a non-magnetic and electrically insulating end plate 9.

[0070] As detailed below, the rotor 5 further includes a first set of slots and a second set of slots arranged in the magnetic blocks to form poles.

[0071] Some of the slots in the first set of slots include a first permanent magnet 12, and some of the slots in the second set of slots include a first permanent magnet 12.

[0072] The non-magnetic and electrically insulating end plate 9 positioned at the end of the stack 7 prevents the axial magnetic flux generated by the first permanent magnet from leaking into the half shafts 6.

[0073] The non-magnetic and electrically insulating end plate 9 has a material that resists the force of the prestress of the stack 7 of laminations 8 and has a low magnetic permeability. For example, the non-magnetic and electrically insulating end plate 9 is made of austenitic stainless steel.

[0074] The rotor 5 further includes a first set of tie rods 100 that connect the two half shafts 6 to keep the laminations 8 of the stack 7 compacted between the two half shafts 6 and pass through the holes of the laminations 8.

[0075] Each tie rod 100 in the first set of tie rods is arranged between two adjacent slots in the first set of slots or the second set of slots.

[0076] The first set of tie rods 100 can be screwed or bolted into the half shafts 6.

[0077] The rotor 5 may further include a non-magnetic retaining ring 13 that encloses the stack 7 of laminations 8 and partially encloses the flanges 10 of the half shafts 6.

[0078] The diameter of the laminations 8 is smaller than the diameter of the flanges 10 such that the inner surface of the retaining ring 13 contacts the peripheral surface of the flanges 10.

[0079] The retaining ring 13 is made of a non-magnetic and electrically insulating material, such as stainless steel or composite fibers such as thermoplastic carbon fiber.

[0080] The retaining ring 13 holds the magnets and laminations 8 that are discharged from the rotor 5 under the action of centrifugal force.

[0081] The rotor 5 including the half shafts 6 and the retaining ring 13 can rotate at a rotational speed such that the peripheral speed of the rotor 5 is greater than 200 m / s -1 , increasing the power density of the rotor 5 compared to the permanent magnet rotors known from the prior art.

[0082] In addition, since the diameter of the laminations 8 is smaller than the inner diameter of the retaining ring 13, the retaining ring 9 allows for the prestress of the stack 7 of laminations 8.

[0083] The stack 7 may further include at least one intermediate non-magnetic and electrically insulating disk 14 to divide the stack 7 into two sub-stacks of laminations 8.

[0084] As shown, the stack 7 includes two intermediate non-magnetic and electrically insulating disks 14 arranged in the stack 7 such that the laminations 8 are divided into three sub-stacks having the same length Ls, and the sum of the lengths Ls of the three sub-stacks is equal to the length Lt of the stack 7.

[0085] In a variant, the length of each sub-stack can be different, and the sum of the lengths of the sub-stacks is equal to the length Lt of the stack 7.

[0086] Each intermediate non-magnetic and electrically insulating disk 14 can be made of a non-magnetic and electrically insulating material, such as stainless steel or a composite material such as thermoplastic carbon fiber.

[0087] The stack 7 can include more than two intermediate non-magnetic and electrically insulating disks 14.

[0088] The diameter of the intermediate non-magnetic and electrically insulating disk 14 is equal to the diameter of the flange 10, such that the retaining ring 13 contacts the peripheral surface of the intermediate non-magnetic and electrically insulating disk 14.

[0089] The intermediate non-magnetic and electrically insulating disk 14 equalizes the prestressing forces of the first set of tie rods on the laminations 8 and is made of, for example, non-magnetic stainless steel.

[0090] As shown in Figure 3 As illustrated above, the cylindrical stack is divided in the longitudinal direction by a plane PL1 including the axis of rotation A into two similar semi-cylinders C1, C2.

[0091] The first pole P1 is arranged in the first semi-cylinder C1, and a second pole P2 similar to the first pole P1 is arranged in the second semi-cylinder C2.

[0092] Each pole P1, P2 includes a first set of slots 15, 15a and a second set of slots 16, 16a, and the first set of slots 15, 15a and the second set of slots 16, 16a include first permanent magnets 12.

[0093] Since the two poles P1, P2 are similar, the first pole P1 is described in detail below.

[0094] The first set of slots 15 is arranged to form a magnetic flux along the straight axis P of the first pole P1 generated by the first set of slots 15 and the second set of slots 16.

[0095] The second set of 16 slots is arranged to provide a separation of the magnetic flux from adjacent poles and is arranged along the intersection axis Q of the first pole P1.

[0096] The slots in the second set of 16 slots are arranged on either side of the slots in the first set of 15.

[0097] The straight axis P is the axis along which the magnets 14 in the first set of 15 slots generate flux.

[0098] Since the rotor 5 is a two-pole permanent magnet rotor, the intersection axis Q is an axis positioned perpendicular to the straight axis P. The intersection axis Q is angularly centered between two adjacent poles P1, P2.

[0099] The angle between the direct axis P and the cross axis Q is equal to 180° divided by the number of poles, the number of poles being even, and the poles form (one or more pairs of) paired poles.

[0100] For example, for a two-pole rotor forming paired poles, such as rotor 5, the angle between the direct axis P and the cross axis Q is equal to 90°, for a four-pole rotor, the angle between the direct axis P and the cross axis Q is equal to 45°, and for a six-pole rotor, the angle between the direct axis P and the cross axis Q is equal to 30°.

[0101] The slots in the first group of 15 slots are arranged perpendicular to the direct axis P.

[0102] At least some of the slots in the first group of slots are arranged to receive corresponding first permanent magnets 14. As shown, each of the slots in the first group of slots 15 includes a first permanent magnet 14.

[0103] The slots in the first group of 15 slots can be stacked one on top of the other along the direct axis P in ascending order of the lengths of the slots in the first group of 15 slots perpendicular to the direct axis P, and the slot having the maximum length perpendicular to the direct axis P in the first group of 15 slots is closest to the rotational axis A, and the slot having the minimum length perpendicular to the direct axis P in the first group of 15 slots is closest to the periphery of the lamination 8.

[0104] At least some of the second group of 16 slots can be arranged with corresponding first permanent magnets 12. In one exemplary embodiment, as shown in Figure 3 each of the slots in the second group of slots 16 includes a first permanent magnet 12. This arrangement results in the maximum magnetic field generated by the poles P1, P2.

[0105] At least some of the slots in the second group of 16 slots extend from a corresponding transition post (e.g., transition post 18), and the corresponding transition post is configured to mechanically transition from the first group of 15 slots to the second group of 16 slots. That is, each transition post provides a structural member between one of the first group of 15 slots and an adjacent one of the second group of 16 slots to support against the expected mechanical forces.

[0106] Each slot of the second group of 16 extending from the corresponding transition post may include a section that extends obliquely with respect to the radius through the corresponding opening that houses a tie rod of the first group, and the tie rod of the first group is positioned along the path of the magnetic flux along the cross axis Q.

[0107] The slots in the second group of 16 slots can be composed of pairs of slots, such as slot pairs 19 and 20 extending from a corresponding central post 21.

[0108] Magnetic flux barriers 22 are arranged at each end of each slot in each of the first group of 15 and the second group of 16 to prevent the axial magnetic flux generated by the first permanent magnets 12 from circulating in the lamination 7, such that the magnetic flux generating torque on the shaft 11 of the half shaft 6 is maximized.

[0109] The magnetic flux barrier 22 can be air or a non-magnetic and electrically insulating wedge inserted into the ends of the slots.

[0110] The first set 15 and the second set 16 of the first pole P1 are symmetric with respect to the first set 15a of slots and the second set 16a of slots of the second pole P2 with respect to the plane PL1.

[0111] Some of the tie rods 100 in the first set of tie rods are arranged between the first pole P1 and the second pole P2.

[0112] Since the rotor 5 includes a non-through rotor shaft composed of two half shafts 6, the laminations 8 do not include a central hole for accommodating a through rotor shaft, so that the first set 15 and the second set 16 include more slots than the permanent magnet rotor known from the prior art without modifying the dimensions of the rotor.

[0113] The volume of the first permanent magnets 12 arranged on the first set 15 and the second set 16 of the poles P1, P2 is increased, so that the magnetic flux delivered by the rotor 5 is increased compared to the permanent magnet rotor known from the prior art, thereby increasing the torque delivered by the electric machine 3 on the shaft 11 of the half shafts 6.

[0114] Since the torque delivered by the machine 3 is increased without modifying the obstruction of the machine 2, the power density of the machine 3 is increased compared to the permanent magnet machine known from the prior art.

[0115] The first permanent magnets 12 and the wedges inserted into the ends of the slots can be firmly connected to the laminations 8 to prevent the first permanent magnets 12 from moving in the slots under the action of centrifugal force.

[0116] The first permanent magnets 12 and the wedges are, for example, bonded in the slots.

[0117] The thickness of the retaining ring 13 is selected to be as thick as possible to increase the amplitude of the magnetic induction generated by the first permanent magnets embedded in the stack 7 in the air gap of the machine 3.

[0118] Furthermore, since the thickness of the retaining ring 13 is reduced, the rotor 5 includes more permanent magnets 12 compared to a rotor of the same size as the rotor 5 known from the prior art.

[0119] Figure 4 Schematically illustrates a cross-section of a second example of the rotor 5 with respect to the radial direction of the rotor 5.

[0120] The second example of the rotor 5 is different from the first example of the rotor 5 illustrated above in that the slots 21 of the second set 16 of the first pole P1 and the second pole P2 closest to the periphery of the stack of laminations include non-magnetic and electrically insulating blocks 23 instead of the first permanent magnets 12. Figure 2 and Figure 3 The second example of the rotor 5 is different from the first example of the rotor 5 illustrated above in that the slots 21 of the second set 16 of the first pole P1 and the second pole P2 closest to the periphery of the stack of laminations include non-magnetic and electrically insulating blocks 23 instead of the first permanent magnets 12.

[0121] Some of the slots 24 in the second set 16 of the first pole P1 and the second pole P2 may include the first permanent magnet 12 and a non-magnetic and electrically insulating block 23.

[0122] In a variant, some of the slots in the second set of slots of the poles P1, P2 include the block 23 instead of the first permanent magnet 12.

[0123] Replacing all or part of the first permanent magnet 12 in some of the slots in the second set 16 of the first pole P1 and the second pole P2 reduces the number of the first permanent magnets 12 in the rotor 5 while retaining the saliency effect.

[0124] The number of the first permanent magnets 12 in the second set 16 replaced by the blocks 23 is determined such that the magnetic flux generated by the first permanent magnets 12 in the rotor 5 is sufficient to drive a mechanical system (such as the compression section 2) connected to one of the half shafts, or to generate the required electrical energy when the rotor 5 is driven by a motor system.

[0125] The blocks 23 inserted into the slots of the second set 16 can be firmly connected to the laminations 8 to prevent the blocks 23 from moving in the slots under the action of centrifugal force.

[0126] The blocks 23 are, for example, incorporated in the slots.

[0127] Figure 5 Schematically illustrates a cross-section of a third example of the rotor 5 with respect to the radial direction of the rotor 5.

[0128] The rotor 5 includes: a first pole P1 and a second pole P2 including a first set of slots and a second set of slots; a third pole P3 and a fourth pole P4 similar to the first pole P1 and the second pole P2.

[0129] The machine 3 including the rotor 5 is a four-pole synchronous permanent magnet machine.

[0130] The cylindrical stack 7 is divided into four similar cylindrical parts C10, C11, C12, C13 in the longitudinal direction of the stack 7.

[0131] The first pole P1 is arranged in the first cylindrical part C10, the second pole P2 is arranged in the second cylindrical part C11, the third pole P3 is arranged in the third cylindrical part C13, and the fourth pole P4 is arranged in the fourth cylindrical part C14.

[0132] The poles P1, P2, P3, P4 are arranged in the cylindrical portions C10, C11, C12, C13 such that the first set of 15 slots and the second set of 16 slots of the first pole P1 and the first set of 15a slots and the second set of 16a slots of the second pole P2 are symmetric with respect to a first plane PL10 including the rotational axis A of the rotor 5, and such that the first set of 15b, 15c slots and the second set of 16b, 16c slots of the third pole P3 and the fourth pole P4 are symmetric with respect to a second symmetry plane PL20 including the rotational axis A and perpendicular to the first plane PL10, relative to the first set of 15, 15a slots and the second set of 16, 16a slots of the first pole P1 and the second pole P2.

[0133] The slots in the first set of 15, 15a, 15b, 15c slots and the second set of 16, 16a, 16b, 16c slots of the poles P1, P2, P3, P4 include permanent magnets 12.

[0134] The rotor 5 may further include a third set of slots 25 that extend along the rotational axis A of the rotor 5 and accommodate rods 26 made of a non-magnetic and electrically insulating material (such as stainless steel or a composite material such as thermoplastic carbon fiber). The rods 26 and the slots 25 may be cylindrical.

[0135] The rotor 5 may further include a fourth set of slots 27a, 27b, 27c, 27d.

[0136] Each slot 27a, 27b, 27c, 27d in the fourth set of slots extends between the rotational axis A of the rotor 5 and the peripheral surface of the stack 7.

[0137] The first slot 27a and the second slot 27b of the fourth set are oriented according to a first plane P10, and the third slot 27c and the fourth slot 27d of the fourth set are oriented according to a second plane P20.

[0138] The first slot 27a of the fourth set is arranged between the first pole P1 and the second pole P2, the second slot 27b of the fourth set is arranged between the third pole P3 and the fourth pole P4, the third slot 27c of the fourth set is arranged between the second pole P2 and the third pole P3, and the fourth slot 27d of the fourth set is arranged between the first pole P1 and the fourth pole P4.

[0139] Each slot 27a, 27b, 27c, 27d in the fourth set of slots includes a third permanent magnet 28 and a magnetic flux barrier 29 arranged at an end of the slot 27a, 27b, 27c, 27d near the peripheral surface of the stack 7.

[0140] The rods 26 and the slots 25 may be cylindrical. The rods 26 prevent magnetic flux leakage generated by the third permanent magnets.

[0141] The rotor 5 includes a first set 15, 15a, 15b, 15c of slots including permanent magnets 12 for poles P1, P2, P3, P4, a second set 16, 16a, 16b, 16c of slots, and a fourth set of slots 27a, 27b, 27c, 27d including a third permanent magnet 28 and a magnetic flux barrier 29, which form a rotor that combines a multi-layer rotor type known from the prior art and a flux concentration type from the prior art. The rotor 5 includes more permanent magnets than rotors known from the prior art.

[0142] 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 is increased compared to a machine with the same obstruction as the machine 3 known from the prior art.

[0143] The third permanent magnet 28 adds a field alignment torque in the direct axis of each pole P1, P2, P3, P4 and a reluctance torque in the quadrature axis of each pole P1, P2, P3, P4 to maximize the amount of torque generated by the rotor 5.

[0144] The second permanent magnet 26 and the third permanent magnet 28 inserted into the ends of the slots can be firmly connected to the lamination 8 to prevent the second permanent magnet 26 and the third permanent magnet 28 from moving in the slots under the action of centrifugal force.

[0145] The second permanent magnet 26 and the third permanent magnet 28 are, for example, incorporated in the slots.

[0146] The stack 7 further includes a second set of tie rods 30 disposed between the axis of rotation A of the rotor and the first pole P1, the second pole P2, the third pole P3, and the fourth pole P4, and between the slots in the fourth set of slots 27a, 27b, 27c, 27d.

[0147] The second set of tie rods 30 connects two non-magnetic and electrically insulating end plates 9 to keep the laminations 8 of the stack 7 compacted between the non-magnetic and electrically insulating end plates 9 and through the holes of the laminations 8.

[0148] The second set of tie rods 30 can be screwed or bolted into the non-magnetic and electrically insulating end plates 9.

[0149] In a variant, the rotor 5 can include more than four poles, the cylindrical stack 7 is divided accordingly, and the number of poles is even. The cylindrical stack 7 is divided in the longitudinal direction of the stack 7 into identical cylindrical parts, the number of which is equal to the number of poles, and each pole is disposed in a cylindrical part. The first set of slots and the second set of slots of one pole are symmetric with respect to a plane including the axis of rotation A of the rotor 5 with respect to the first set of slots and the second set of slots of an adjacent pole, and this plane separates the cylindrical parts of the one pole and the adjacent pole.

[0150] Figure 6 An example of the magnetic coupler 40 is illustrated.

[0151] The magnetic coupler 40 includes an outer rotor 41.

[0152] The rotor 5 is inserted into the outer rotor 41.

[0153] The torque applied to one of the rotor 5 and the outer rotor 41 is transmitted to the other rotor through the air gap.

Claims

1. Rotor (5), comprising: - A cylindrical stack (7) of laminations (8), said cylindrical stack (7) comprising: ○ At least a first set (15) of slots and a second set (16) of slots, said first set (15) of slots and said second set (16) of slots being arranged to form a first pole (P1), said first set of slots being arranged to form a magnetic flux along the direct axis (P) of the pole produced by said first set of slots and said second set of slots, at least some of said first set of slots comprising a first permanent magnet (12), said second set of slots being arranged to provide a separation of the magnetic flux from an adjacent pole and being disposed along the cross axis (Q) of the pole, and at least some of said second set of slots comprising a first permanent magnet, and ○ At least a second pole (P2), said first pole (P1) and said second pole (P2) forming a pair of poles of said rotor (5), characterized in that the rotor further comprises: - A magnetic flux barrier (22), said magnetic flux barrier (22) being disposed at each end of each slot in said first set of slots and said second set of slots, - Two half shafts (6), said two half shafts (6) enclosing said stack of laminations and forming the shaft of said rotor, said 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 interposed between one end of said stack and a half shaft, and - A first set of tie rods (100), said first set of tie rods (100) connecting said two half shafts to keep said laminations of said stack compacted between said two half shafts, each tie rod in said first set of tie rods being disposed between two adjacent slots in said first set of slots or said second set of slots.

2. The rotor according to claim 1, wherein, At least some of the slots in said second set (16) of slots closest to the periphery of said stack (7) of laminations (8) comprise non-magnetic and electrically insulating blocks (23).

3. The rotor according to claim 1 or 2, wherein, Each half shaft (6) comprises a flange (10) in contact with a non-magnetic and electrically insulating end disc (9), and the rotor further comprises a non-magnetic retaining ring (13), said non-magnetic retaining ring (13) enclosing said stack (7) of laminations (8) and partially enclosing said flange of said half shaft, the diameter of said stack of laminations being smaller than the diameter of said flange, such that the inner surface of said retaining ring contacts the peripheral surface of said flange, said retaining ring being made of a non-magnetic and electrically insulating material.

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

5. The rotor according to claim 3, wherein, Said retaining ring (13) is made of composite fibers.

6. The rotor according to any one of claims 3 to 5, wherein, Said laminations (8) of said stack (7) are separated into two sub-stacks of laminations by at least one intermediate non-magnetic and electrically insulating disc (14), the diameter of said intermediate non-magnetic and electrically insulating disc being equal to the diameter of said flange (10), such that said retaining ring contacts the peripheral surface of said intermediate non-magnetic and electrically insulating disc.

7. The rotor according to any one of claims 1 to 6, wherein, The cylindrical stack (7) is divided in the longitudinal direction of the stack into two similar semi-cylinders (C1, C2) by a plane (PL1) including the rotational axis (A) of the rotor, the first pole (P1) being arranged in the first semi-cylinder (C1), the second pole (P2) being arranged in the second semi-cylinder (C2) and being similar to the first pole, the first set (15) of slots and the second set (16) of slots of the first pole (P1) being symmetric with respect to the plane (PL1) to the first set (15a) of slots and the second set (16a) of slots of the second pole (P2), the tie rods in the first set of tie rods (100) being arranged between the first pole and the second pole.

8. The rotor according to any one of claims 1 to 6 further includes a third pole (P3) and a fourth pole (P4) similar to the first pole (P1), and the second pole (P2) is similar to the first pole (P1), wherein, The cylindrical stack (7) is divided in the longitudinal direction of the stack into four similar cylindrical parts (C10, C11, C12, C13), the first pole (P1) being arranged in the first cylindrical part (C10), the second pole (P2) being arranged in the second cylindrical part (C11), the third pole (P3) being arranged in the third cylindrical part (C12), the fourth pole (P4) being arranged in the fourth cylindrical part (C13), such that the first set (15) of slots and the second set (16) of slots of the first pole (P1) are symmetric with respect to a first plane (PL10) including the rotational axis (A) of the rotor to the first set (15a) of slots and the second set (16a) of slots of the second pole (P2), and the first set (15b, 15c) of slots and the second set (16b, 16c) of slots of the third pole (P3) and the fourth pole (P4) are symmetric with respect to a second symmetry plane (PL20) including the rotational axis (A) of the rotor and perpendicular to the first plane to the first set of slots and the second set of slots of the first pole and the second pole.

9. The rotor according to claim 8, further comprising a third set of slots (25) extending along the rotational axis (A) of the rotor (5) and accommodating a second permanent magnet (26).

10. The rotor according to claim 8 or 9, further comprising a fourth set of slots (27a, 27b, 27c, 27d), each slot in the fourth set of slots extending between the rotational axis (A) of the rotor and the peripheral surface of the stack (7) and being oriented according to the first plane (PL10) or the second plane (PL20), each slot in the fourth set of slots comprising a third permanent magnet (28) and a magnetic flux barrier (29) arranged at the end of each slot in the fourth set of slots close to the peripheral surface of the stack.

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