Winding field rotor

Abstract

To properly wind a wire to a rotor core and a field coil.SOLUTION: A rotor 60 comprises: a rotor core 61 including a plurality of main pole parts 62; a field coil 70 which is provided while circulating over the main pole parts 62; an outer peripheral cover part 102 which is configured by spirally winding a wire 131 radially outside of the main pole parts 62 and the field coil 70; and a coil end cover 104 which covers a coil end of the field coil 70. The outer peripheral cover part 102 and the coil end cover 104 are provided continuously in an axial direction radially outside of the field coil 70. The wire 131 is wound in a range radially overlapping the rotor core 61 in the axial direction, pulled out in the axial direction along an outer peripheral surface of the coil end cover 104 axially outside of the outer peripheral cover part 102 and fixed to the coil end cover 104 at a position inside of an outer peripheral surface of the outer peripheral cover part 102 in a radial direction.SELECTED DRAWING: Figure 11

Description

[Technical Field]

[0001] The disclosure herein relates to wound field rotors. [Background technology]

[0002] A wound-field rotating electric machine has a stator with a stator winding and a rotor with a field winding. The rotor has a rotor core with multiple main poles (magnetic salient poles), and the field winding is wound around the main poles. Patent Document 1 also discloses a rotor structure in which a metal wire is wound spirally around the outer periphery of the field winding, and the ends of the wire are fixed to end plates by bolts or welding. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-9553 Summary of the Invention [Problem to be solved by the invention]

[0004] In the technology described in Patent Document 1, the wire is wound multiple times in an area that extends beyond the rotor core in the axial direction, and the ends of the wire are fixed to the end plates in this state. In this case, the wire is wound with a certain degree of strength to prevent loosening of the wire. However, unlike the rotor core area, there is a concern that the end plates may be deformed due to the winding of the wire axially outside the rotor core. Note that if the end plates are thickened to increase their strength, there is likely to be room for improvement in terms of weight and cooling performance.

[0005] The present disclosure has been made in consideration of the above circumstances, and has an object to provide a wound field rotor that allows wire to be properly wound around the rotor core and field winding. [Means for solving the problem]

[0006] The present disclosure provides: a rotor core having a plurality of main pole portions provided for magnetic poles aligned in the circumferential direction; a field winding provided around each of the main pole portions; an outer covering portion formed by spirally winding a wire around the radially outer sides of the main pole portions and the field winding; a coil end cover that covers a coil end of the field winding that is axially outer than the rotor core; A wound field rotor comprising: the outer circumferential covering portion and the coil end cover are provided radially outside the field winding and continuously in the axial direction with their axial end faces facing each other, The wire is wound around the rotor core in the axial direction in an overlapping range in the radial direction, and is pulled out axially along the outer peripheral surface of the coil end cover axially outside the outer peripheral covering portion, and is fixed to the coil end cover at a position radially inside the outer peripheral surface of the outer peripheral covering portion.

[0007] In the rotor, an outer circumferential coating portion formed by winding wire around each main pole and the field winding, and a coil end cover covering the coil end of the field winding, are provided radially outward of the field winding, and are axially continuous with their axial end faces facing each other. In this case, the wire is wound around the rotor core in an overlapping area in the axial direction, so that even if the wire is wound with sufficient strength to prevent slack, deformation of the coil end cover does not occur. Furthermore, the wire is pulled out axially along the outer circumferential surface of the coil end cover axially outward of the outer circumferential coating portion and is fixed to the coil end cover at a position radially inward from the outer circumferential surface of the outer circumferential coating portion. This prevents the pulled end of the wire from protruding radially beyond the outer circumferential surface of the outer circumferential coating portion, thereby suppressing interference with the stator. As a result, the wire can be properly wound around the rotor core and the field winding. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is an overall configuration diagram of a control system for a rotating electrical machine. [Figure 2] FIG. 2 is a diagram showing an inverter and its peripheral configuration. [Figure 3] FIG. [Figure 4] FIG. 3 is a diagram showing an electric circuit provided in the rotor. [Figure 5] FIG. 2 is a perspective view showing the overall configuration of the rotor. [Figure 6] FIG. 4 is a perspective view showing a rotor with an outer circumferential covering portion and a coil end cover removed. [Figure 7] FIG. [Figure 8] FIG. [Figure 9] FIG. 3 is an exploded perspective view of a winding unit in the rotor main portion. [Figure 10] FIG. 3 is a cross-sectional view showing a cross-sectional structure of a part of a rotor main portion. [Figure 11] FIG. [Figure 12] FIG. [Figure 13] FIG. 4 is a perspective view showing the configuration of a coil end cover. [Figure 14] FIG. 4 is a plan view of the coil end cover as seen from the inside of the cover. [Figure 15] FIG. 4 is a longitudinal cross-sectional view showing a state in which a coil end cover is attached to the rotor. [Figure 16] FIG. 10 is a diagram showing the relationship between the stress σ at the bend top and the bending angle θ in a wire. [Figure 17] FIG. DETAILED DESCRIPTION OF THE INVENTION

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A wound-field rotating electric machine according to an embodiment of the present disclosure is used as a power source for driving electric vehicles such as electric vehicles and hybrid vehicles.

[0010] First, a control system including a rotating electric machine will be described with reference to Fig. 1. The control system includes a DC power supply 10, an inverter 20, a control device 30, and a rotating electric machine 40. The rotating electric machine 40 is a self-excited wound field type synchronous machine. For example, the rotating electric machine 40, the inverter 20, and the control device 30 may be configured as an electromechanical integrated drive device, or the rotating electric machine 40, the inverter 20, and the control device 30 may each be configured with its own component.

[0011] The rotating electric machine 40 includes a housing 41, and a stator 50 and a rotor 60 housed in the housing 41. The rotating electric machine 40 of this embodiment is an inner rotor type rotating electric machine in which the rotor 60 is disposed radially inside the stator 50.

[0012] The stator 50 includes a stator core 51 and a stator winding 52. The stator winding 52 is made of, for example, copper wire, and includes U-, V-, and W-phase windings 52U, 52V, and 52W that are arranged with an electrical angle offset of 120° from one another.

[0013] The rotor 60 includes a rotor core 61 and a field winding 70. The field winding 70 is preferably made of a conductor material such as aluminum wire, which has a low specific gravity and is easily formed. The conductor material of the field winding 70 is not limited to aluminum wire, and may be, for example, copper wire or CNT (carbon nanotube). A rotating shaft 32 is assembled in the center hole of the rotor core 61. The rotating shaft 32 is rotatably supported in the housing 41 by bearings 42 and 43.

[0014] As shown in FIG. 2, the inverter 20 includes a series connection of upper-arm switches SUp, SVp, and SWp for U, V, and W phases and lower-arm switches SUn, SVn, and SWn for U, V, and W phases. First ends of U, V, and W-phase windings 52U, 52V, and 52W are connected to the connection points between the upper-arm switches SUp, SVp, and SWp and the lower-arm switches SUn, SVn, and SWn for each phase. Second ends of the U, V, and W-phase windings 52U, 52V, and 52W are connected at the neutral point. That is, in this embodiment, the stator winding 52 is star-connected. However, the stator winding 52 may also be delta-connected. In this embodiment, each of the switches SUp to SWn is, for example, an IGBT. A freewheel diode is connected in antiparallel to each of the switches SUp to SWn.

[0015] The collectors of the upper arm switches SUp, SVp, SWp of each phase are connected to the positive terminal of a DC power supply 10. The emitters of the lower arm switches SUn, SVn, SWn of each phase are connected to the negative terminal of the DC power supply 10. A smoothing capacitor 11 is connected in parallel to the DC power supply 10.

[0016] Next, the stator 50 and the rotor 60 will be described with reference to FIG.

[0017] The stator 50 and the rotor 60 are both arranged coaxially with the rotating shaft 32. In the following description, the direction in which the rotating shaft 32 extends is referred to as the axial direction, the direction extending radially from the center of the rotating shaft 32 is referred to as the radial direction, and the direction extending circumferentially around the rotating shaft 32 is referred to as the circumferential direction.

[0018] The stator core 51 is made of laminated steel plates made of a soft magnetic material and has an annular back yoke 51a and multiple teeth 51b protruding radially inward from the back yoke 51a. Multiple slots 54 are formed between adjacent teeth 51b in the circumferential direction. The stator winding 52 is formed by accommodating the phase windings of each phase in a predetermined order in each of these slots 54. For example, the stator 50 may employ a segment coil structure using multiple conductor segments. However, the structure of the stator winding 52 is arbitrary.

[0019] The rotor core 61 is made of a soft magnetic material, for example, laminated steel plates. The rotor core 61 has a cylindrical portion 61a and a plurality of main pole portions 62 extending radially outward from the cylindrical portion 61a. A field winding 70 is wound around the main pole portions 62 by concentrated winding. In this embodiment, eight main pole portions 62 are provided at equal intervals in the circumferential direction.

[0020] The field winding 70 includes a first winding portion 71 and a second winding portion 72. The first winding portion 71 is wound radially outward around each main pole portion 62, and the second winding portion 72 is wound radially inward relative to the first winding portion 71. In each main pole portion 62, the winding directions of the conductor wire in the first winding portion 71 and the second winding portion 72 are the same. Furthermore, among circumferentially adjacent main pole portions 62, the winding direction of each winding portion 71, 72 wound around one is opposite to the winding direction of each winding portion 71, 72 wound around the other. Therefore, the magnetization directions of circumferentially adjacent main pole portions 62 are opposite to each other. In the rotor 60, each main pole portion 62 in the rotor core 61 and the field winding 70 wound around each main pole portion 62 form a plurality of magnetic poles (field poles) arranged in the circumferential direction.

[0021] 4 is a diagram showing an electric circuit including the first and second winding portions 71 and 72 in the rotor 60. The first winding portion 71 and the second winding portion 72 are connected in series by connecting the second end 71b of the first winding portion 71 to the first end 72a of the second winding portion 72. A diode 91 and a capacitor 92 are connected to the second end 71b of the first winding portion 71 in parallel with the second winding portion 72. A diode 93 and a capacitor 94 are connected in series to the series connection of the first winding portion 71 and the second winding portion 72. The capacitors 92 and 94 are, for example, ceramic capacitors or film capacitors.

[0022] The cathode of the diode 91 is connected to the first end 72a of the second winding portion 72, and the anode is connected to the second end 72b of the second winding portion 72. As a result, in a closed circuit including the second winding portion 72 and the diode 91, current flows in one direction, from the anode side to the cathode side of the diode 91. Furthermore, the cathode of the diode 93 is connected to the first end 71a of the first winding portion 71, and the anode is connected to the second end 72b of the second winding portion 72. As a result, the field current flowing through each of the winding portions 71, 72 is rectified. In this embodiment, the number of windings of the second winding portion 72 is greater than the number of windings of the first winding portion 71.

[0023] Returning to the description of FIG. 2 , the control device 30 is an electronic control unit (EC) primarily composed of a microcomputer 31. The microcomputer 31 includes a central processing unit (CPU). The functions provided by the microcomputer 31 can be provided by software stored in a physical memory device and a computer executing the software, software alone, hardware alone, or a combination thereof. For example, if the microcomputer 31 is provided by hardware electronic circuits, the functions can be provided by digital circuits including multiple logic circuits or analog circuits. For example, the microcomputer 31 executes programs stored in a non-transitory tangible storage medium (NSS) that serves as its own storage unit. The programs include programs for controlling the rotating electric machine 40. A method corresponding to the programs is performed by executing a set of instructions that constitute the programs. The storage unit is, for example, a non-volatile memory. The programs stored in the storage unit can be updated via a communication network such as the Internet, for example, via OTA (Over The Air) or other means.

[0024] Control device 30 generates drive signals that turn on and off each of switches SUp to SWn that constitute inverter 20. Specifically, control device 30 generates drive signals that turn on and off each of switches SUp to SWn and outputs the generated drive signals to the gates of each of switches SUp to SWn in order to convert DC power output from DC power supply 10 into AC power and supply it to U-, V-, and W-phase windings 52U, 52V, and 52W. As a result, in each phase, the upper arm switches and the lower arm switches are alternately turned on with dead times therebetween.

[0025] Control device 30 turns on and off each of switches SUp to SWn so as to pass a composite current of a fundamental current and a high-frequency current (specifically, a high-frequency excitation current) having a frequency higher than that of the fundamental current through each of phase windings 52U, 52V, 52W. The fundamental current is a current that mainly serves to generate torque in rotating electric machine 40. The high-frequency current is a current that mainly serves to excite first and second winding portions 71 and 72 that constitute field winding 70, thereby inducing a field current in field winding 70. The phase currents flowing through phase windings 52U, 52V, 52W are shifted by 120 electrical degrees.

[0026] The high-frequency current flowing through the stator winding 52 may be a harmonic current whose fluctuating frequency is N times (N is an integer greater than or equal to 2) the frequency of the fundamental current, or may be a current whose fluctuating frequency is different from N times the frequency of the fundamental current.

[0027] When a high-frequency current flows through the stator winding 52, a voltage is induced in the first and second winding portions 71 and 72, causing a field current to flow. The induced voltages in the first and second winding portions 71 and 72 are, for example, in phase. The currents IL1 and IL2 flowing through the first and second winding portions 71 and 72 contain frequency components of the high-frequency current.

[0028] 4, when the first and second winding portions 71, 72 are excited by energizing the stator winding 52, a current flows from the first winding portion 71 to the second winding portion 72. Furthermore, when the voltage across the second winding portion 72 exceeds the forward voltage of the diode 91, a current IL2, which is greater than the current IL1 flowing through the first winding portion 71, flows through the closed circuit including the second winding portion 72 and the diode 91. The flow of current through the closed circuit including the second winding portion 72 and the diode 91 increases the DC component of the field current. This increases the DC component of the magnetic flux of the rotor 60, thereby increasing the torque of the rotating electric machine 40.

[0029] Next, the configuration of the rotor 60 will be described in more detail. Fig. 5 is a perspective view showing the overall configuration of the rotor 60, and Fig. 6 is a perspective view showing the rotor 60 with the outer covering portion 102 that covers the rotor main portion 101 and the coil end covers 103, 104 removed. Fig. 7 is an exploded perspective view of the rotor 60, and Fig. 8 is a vertical cross-sectional view of the rotor 60.

[0030] The rotor 60 is broadly divided into a rotor main section 101, a cylindrical outer covering section 102 provided to surround the outer periphery of the rotor main section 101, coil end covers 103 and 104 attached to one and the other axial ends of the rotor main section 101, and a busbar module 105 and a circuit module 106 provided at one of both axial ends of the rotor main section 101. The rotor main section 101 includes a rotor core 61 and a field winding 70, and the rotating shaft 32 is attached to the center hole of the rotor core 61. The field winding 70 is made up of a plurality of winding units 110 arranged in a circumferential direction. The coil end covers 103 and 104 are provided to cover the coil ends of the field winding 70 on both axial sides.

[0031] The busbar module 105 and the circuit module 106 are fixed to the rotating shaft 32 with the rotating shaft 32 inserted through each hollow portion, so that the busbar module 105 and the circuit module 106 are provided at positions axially facing the coil end portions of the field winding 70. The busbar module 105 has a plurality of bus bars for electrically connecting the winding units 110 for each magnetic pole.

[0032] The circuit module 106 has a component holder 107 that houses electrical components, and a heat sink 108 that is placed over the component holder 107. The component holder 107 and the heat sink 108 are integrated with their axial end faces joined together. The component holder 107 holds diodes 91 and 93 and capacitors 92 and 94 as electrical components.

[0033] Heat sink 108 is fixed to one of the axial ends of component holder 107, on the side opposite rotor core 61 (the right side in the figure). Heat sink 108 is made of, for example, aluminum. By fixing heat sink 108 to the axial end face of component holder 107, heat generated in diodes 91 and 93 and capacitors 92 and 94 when current is applied to component holder 107 is released via heat sink 108.

[0034] The outer covering portion 102 is made of a metal wire and is configured by winding the wire in multiple layers around the outer periphery of a plurality of winding units 110 assembled to the rotor core 61. Details of the outer covering portion 102 will be described later.

[0035] Fig. 9 is an exploded perspective view of the winding unit 110 in the rotor main section 101, and Fig. 10 is a cross-sectional view showing the cross-sectional structure of a portion of the rotor main section 101. Note that Fig. 10 depicts the outer circumferential covering section 102 shown in Fig. 5 and other figures as a structure for holding the field winding 70 wound around the main pole section 62 of the rotor core 61.

[0036] The rotor main section 101 has a plurality of winding units 110, one for each magnetic pole of the rotor 60. Each winding unit 110 is formed in an annular shape with the axial direction as the longitudinal direction, and is assembled to the rotor core 61 with the main pole section 62 of the rotor core 61 inserted into its hollow section. In this embodiment, the winding units 110 form a "pole coil."

[0037] The winding unit 110 has a first coil module 111 that is on the radially outer side when attached to the main pole section 62, and a second coil module 112 that is on the radially inner side. The first coil module 111 is a coil module that corresponds to the first winding section 71, and the second coil module 112 is a coil module that corresponds to the second winding section 72.

[0038] The first coil module 111 has an annular coil body 121 formed by winding a conductor material made of a rectangular wire multiple times in the circumferential and radial directions, and a thin plate-like insulator 122 provided integrally with the coil body 121. The insulator 122 has a portion that extends circumferentially and covers the outer peripheral portions on the radially outer and inner sides of the coil body 121, and a portion that extends radially and covers the hollow portion of the coil body 121. In other words, the outer peripheral portion on the radially outer side, the inner peripheral portion on the radially inner side, and the hollow portion of the coil body 121 are insulated and coated with the insulator 122.

[0039] The second coil module 112 has an annular coil body 123 formed by winding a conductor material made of a rectangular wire multiple times in the circumferential and radial directions, and a thin plate-like insulator 124 provided integrally with the coil body 123. The insulator 124 has a portion that extends circumferentially and covers the outer peripheral portions on the radially outer and inner sides of the coil body 123, and a portion that extends radially and covers the hollow portion of the coil body 123. In other words, the outer peripheral portion on the radially outer side and the inner peripheral portion and hollow portion of the coil body 123 are insulated and coated with the insulator 124.

[0040] The coil body 121 of the first coil module 111 is, for example, an α-winding coil in which a conductive wire is wound in an α-winding manner. The coil body 123 of the second coil module 112 is a continuously wound coil in which a conductive wire is continuously wound in a predetermined circumferential direction. In the first coil module 111, two conductive wire ends 125 are drawn out in the axial direction, and in the second coil module 112, two conductive wire ends 126 are drawn out in the axial direction. In each of the winding units 110 arranged in the circumferential direction, the conductive wire ends 125, 126 are connected to each other, so that the multiple first coil modules 111 provided on each main pole part 62 are connected in series, and the multiple second coil modules 112 provided on each main pole part 62 are connected in series.

[0041] The conductor wire used for the coil bodies 121, 123 is, for example, a flat wire having a substantially rectangular cross section (specifically, a substantially rectangular shape). The flat wire is composed of a conductor portion made of aluminum or the like and an insulating layer covering the conductor portion. However, a round wire having a circular cross section can also be used as the conductor wire. Note that the coil structure of each coil module 111, 112 is optional; for example, the coil bodies 121, 123 can both be continuous wound coils.

[0042] As shown in Fig. 10, the first coil module 111 has two radially wound layers of conductive wire, while the second coil module 112 has twelve radially wound layers of conductive wire. The number of layers in each of the coil modules 111, 112 is arbitrary, but it is preferable that the number of layers in the second coil module 112 is greater than the number of layers in the first coil module 111. The coil modules 111, 112 have different numbers of circumferential windings (in other words, the number of rows of conductive wire in the circumferential direction), with the number of windings being greater on the radially outer side than on the radially inner side. This improves the space factor of the field winding 70.

[0043] Next, we will explain the outer circumferential covering portion 102 and the coil end covers 103, 104 that are provided to surround the rotor core 61 and the field winding 70 in the rotor 60. Fig. 11 is a perspective view of the rotor 60, with the coil end cover 104 on the opposite side of the circuit module 106, of the coil end covers 103, 104 on both axial sides, facing forward.

[0044] The rotor 60 is provided with coil end covers 103, 104 on both axial sides of the outer circumferential covering portion 102. The axial range in which the outer circumferential covering portion 102 is provided is a range that radially overlaps with the rotor core 61, and this range X is shown in Figure 8. In range X, the main pole portions 62 and winding units 110 are lined up in the circumferential direction, and the outer circumferential covering portion 102 is formed by spirally and multiple-wound wire 131 around the radial outside of each of the main pole portions 62 and winding units 110.

[0045] Specifically, the outer covering portion 102 may be configured as shown in FIG. 12 . FIG. 12 is a longitudinal cross-sectional view of the outer covering portion 102, with the left-right direction being the axial direction and the up-down direction being the radial direction. In FIG. 12 , the wire materials 131 are wound in multiple layers (four layers in the figure) in the radial direction while contacting each other in the axial direction. The wire materials 131 may be flat steel wires having a rectangular cross section. The wire materials 131 may also be magnetic materials, specifically, SUS430, SUS631, piano wire, or the like. Using flat wires as the wire materials 131 reduces the likelihood of gaps forming between the wire materials 131 in the outer covering portion 102. This prevents the wire materials 131 from collapsing or deforming in the outer covering portion 102. Furthermore, the space factor of the outer covering portion 102 is increased, thereby enhancing the strength of the outer covering portion 102.

[0046] Furthermore, in the outer circumferential covering portion 102, the wire rods 131 are wound in a state where they are linearly aligned in both the axial and radial directions. In this case, since the wire rods 131 are wound in a state where they are aligned in the axial direction, the outer circumferential surface (the circumferential surface on the outer radial side) of the outer circumferential covering portion 102 becomes flat. Therefore, the mechanical space between the rotor 60 and the stator 50 (the gap between the outer circumferential surface of the outer circumferential covering portion 102 and the stator 50) can be made constant in the axial direction. Furthermore, since the wire rods 131 are wound in a state where they are aligned in the radial direction, the outer circumferential covering portion 102 is divided at predetermined intervals in the axial direction. Therefore, eddy currents are reduced in the outer circumferential covering portion 102.

[0047] The outer covering portion 102 and the coil end covers 103, 104 are provided radially outside the main pole portion 62 and the field winding 70, and are continuous in the axial direction with their axial end faces facing each other.

[0048] In the outer circumferential covering portion 102, the axial end portions in the range X are the winding start and winding end positions of the wire rod 131. In this embodiment, of the axial ends of the outer circumferential covering portion 102 on the coil end cover 104 side, the winding start and winding end positions of the wire rod 131 are the winding start and winding end positions. Fig. 11 shows the wire rod 131 extending in the axial direction from the winding start and winding end positions.

[0049] The wire rods 131 are pulled out in the axial direction along the outer peripheral surface of the coil end cover 104, axially outside the outer peripheral covering portion 102, and are fixed to the coil end cover 104. The structure for fixing the wire rods 131 to the coil end cover 104 will be described below. First, the configuration of the coil end cover 104 will be described using Figures 13 to 15. Figure 13 is a perspective view showing the configuration of the coil end cover 104, Figure 14 is a plan view of a portion of the coil end cover 104 as seen from the inside of the cover, and Figure 15 is a vertical cross-sectional view showing the state in which the coil end cover 104 is attached to the rotor 60.

[0050] The coil end cover 104 has an end plate portion 141 that is fixed to the rotating shaft 32, and an annular portion 142 that extends axially from the outer periphery of the end plate portion 141 and surrounds the coil ends (rotor coil ends RE) of the field winding 70 from the radially outer side. In the coil end cover 104, the end plate portion 141 is a portion that faces the rotor coil ends RE in the axial direction, and the annular portion 142 is a portion that surrounds the rotor coil ends RE from the radially outer side. The end plate portion 141 extends radially while being fixed to the rotating shaft 32, and has a center hole 143 that penetrates in the plate thickness direction at its radial center. The coil end cover 104 is fixed to the rotating shaft 32 by press-fitting the end plate portion 141, fastening with screws, or the like, with the rotating shaft 32 inserted through the center hole 143 of the end plate portion 141. The annular portion 142 is attached to the axial end of the winding unit 110 (more specifically, the axial end of the insulator 122 of the first coil module 111).

[0051] In the coil end cover 104, an inclined surface 144 is formed on the outer circumferential side of the annular portion 142, which is inclined with respect to the axial direction and approaches the rotor axis center on the side of the end plate portion 141, and the wire rod 131 is drawn out in the axial direction along the inclined surface 144. The annular portion 142 is formed with seat portions 145 at equal intervals in the circumferential direction (specifically, every 90°), and the outer surfaces of the seat portions 145 form the inclined surface 144.

[0052] A protruding portion 146 that protrudes in the radial direction is provided on the base portion 145. The protruding portion 146 is provided on the inclined surface 144 and serves as a hook portion that can hook the wire 131 in the circumferential direction.

[0053] 15 , the wire 131 is drawn from the annular portion 142 to the end plate portion 141 of the coil end cover 104, and a wire tip portion 132, which is the portion of the wire 131 on the leading end side, is fixed by welding to the end plate portion 141. In this case, the wire 131 is drawn in the axial direction along the outer circumferential surface of the coil end cover 104, axially outside the outer circumferential covering portion 102, and is fixed to the coil end cover 104 at a position radially inside the outer circumferential surface of the outer circumferential covering portion 102.

[0054] The wire tip portion 132 is welded to a plane perpendicular to the axial direction in the coil end cover 104. This configuration makes the welding process easier than when the wire tip portion 132 is welded to a plane inclined relative to the axial direction, enabling improvements in quality and manufacturability.

[0055] The wire material 131 is pulled out in the axial direction at a position on the side of the protruding portion 146. Therefore, the protruding portion 146 suppresses circumferential positional deviation of the wire material 131. Note that the protruding portions 146 may be provided so as to sandwich the wire material 131 from both sides in the circumferential direction.

[0056] 14, in the annular portion 142 of the coil end cover 104, large diameter portions 151 having a large radial dimension from the rotor axis center to the outer periphery and small diameter portions 152 having a small radial dimension are alternately provided in the circumferential direction at the opposing portion (i.e., the axial end face) that axially faces the outer periphery covering portion 102. The large diameter portions 151 are arc portions having substantially the same outer diameter dimension as the outer periphery covering portion 102, and the small diameter portions 152 are chord portions between two circumferentially adjacent large diameter portions 151. The wire rod 131 is then drawn out in the axial direction from the small diameter portions 152.

[0057] That is, in the annular portion 142 of the coil end cover 104, a small diameter portion 152 is formed for each winding unit 110 of each magnetic pole, and a large diameter portion 151 is formed between circumferentially adjacent small diameter portions 152. In this case, in the coil end cover 104, the portion that is radially outward of the coil end of each winding unit 110 is a flat portion that extends in a direction perpendicular to the extension direction of the main pole portion 62, and the wire 131 is drawn out in the axial direction from this flat portion.

[0058] The large diameter portion 151 of the annular portion 142 faces the outer circumferential covering portion 102 in the axial direction, which prevents the wire rod 131 from becoming unwound in the outer circumferential covering portion 102. Furthermore, the wire rod 131 is pulled out in the axial direction from the small diameter portion 152 of the annular portion 142, which allows the wire rod 131 to be pulled from the outer circumferential covering portion 102 side to the coil end cover 104 side without expanding in the radial direction.

[0059] 15, the wire rod 131 is bent between the portion extending along the annular portion 142 and the portion extending along the end plate portion 141, and the bending angle θ is preferably 135° or less (0 to 135°). More preferably, the bending angle θ is within the range of 90° to 135°. In other words, the wire rod 131 is drawn out in the axial direction along the outer surface of the coil end cover 104, and is welded and fixed at a position closer to the tip end than the apex of the bend bent at a bending angle θ of 135° or less or within the range of 90° to 135°.

[0060] Figure 16 shows the relationship between the bending angle θ of the wire 131 and the stress σ generated at the bend apex when the wire 131 is pulled in the longitudinal direction of the wire. According to the figure, by setting the bending angle θ to 135° or less, the stress σ at the bend apex is maintained at a high level, thereby reducing the stress applied to the welded portion of the wire tip 132. Figure 16 shows the results of an analysis of the relationship between the bending angle θ and the stress σ at the bend apex, using a rectangular steel wire as the wire 131 and setting the following analytical conditions: cross-sectional size: 0.6 mm × 0.7 mm, friction coefficient: 0.5, tensile load: 200 N, bend radius: 1 mm, and wire length: 10 mm.

[0061] By setting the bending angle of the wire 131 as described above, even if centrifugal force acts on the drawn-out portion of the wire 131 when the rotor 60 rotates, the tensile stress of the wire 131 is reduced at the bent apex, thereby reducing the load on the welded portion of the wire tip 132.

[0062] 13 to 15, in the coil end cover 104, the end plate portion 141 is provided with inlet ports 161 for allowing the refrigerant to flow into the space S within the cover between the coil end cover 104 and the coil end of the field winding 70, and the annular portion 142 is provided with outlet ports 162 for allowing the refrigerant to flow from the space S within the cover to the outside of the cover. More specifically, the end plate portion 141 is formed with the inlet ports 161 as a refrigerant flow path for passing the refrigerant so as to pass through the end plate portion 141. The inlet ports 161 are formed in an annular shape so as to surround the rotating shaft 32. In addition, the annular portion 142 of the coil end cover 104 is formed with outlet ports 162 at predetermined intervals in the circumferential direction.

[0063] The rotating electrical machine system has a refrigerant circulation path through which the refrigerant is circulated by driving a circulation pump. In the rotating electrical machine 40, the refrigerant flowing through the refrigerant circulation path within the housing 41 is sprayed axially onto the coil end cover 104.

[0064] As shown in Figure 15, when refrigerant is sprayed onto the coil end cover 104 in the axial direction, the refrigerant flows into the space S within the cover through the inlet 161 of the coil end cover 104, cools the rotor coil ends RE, and then flows out of the cover through the outlet 162 (see Figure 11) due to centrifugal force caused by rotor rotation. At this time, the refrigerant cools the rotor coil ends RE as well as the coil end cover 104. Cooling the coil end cover 104 suppresses thermal contraction of the lead-out portions of the wire 131 that are provided along the coil end cover 104.

[0065] The coil ends of the stator winding 52 are arranged radially outside the rotor coil ends RE, and the stator winding 52 is cooled by the refrigerant that flows out from the outer periphery of the coil end cover 104 to the outside of the cover.

[0066] According to the present embodiment described above in detail, the following excellent effects can be obtained.

[0067] In the rotor 60, the outer circumferential covering portion 102 and the coil end cover 104 are provided axially continuous with their axial end faces facing each other, and the wire 131 of the outer circumferential covering portion 102 is wound around the rotor core 61 in the axial direction in a radially overlapping range. This configuration prevents deformation of the coil end cover 104 even when the wire 131 is wound with sufficient strength to prevent loosening. Furthermore, the wire 131 is pulled out in the axial direction along the outer circumferential surface of the coil end cover 104 on the axially outer side of the outer circumferential covering portion 102 and fixed to the coil end cover 104 at a position radially inward of the outer circumferential surface of the outer circumferential covering portion 102. This prevents the pulled end of the wire 131 from protruding beyond the outer circumferential surface of the outer circumferential covering portion 102, thereby suppressing interference with the stator 50. As a result, the wire 131 can be properly wound around the rotor core 61 and the field winding 70.

[0068] In the coil end cover 104, an inclined surface 144 is provided on the outer peripheral surface of the annular portion 142, and the wire 131 is configured to be drawn out in the axial direction along the inclined surface 144. In this case, compared to a configuration in which the outer peripheral surface of the annular portion 142 is provided parallel to the axial direction, the drawn-out portion of the wire 131 is farther away from the stator 50. This makes it possible to suitably suppress contact of the wire 131 with the stator 50.

[0069] In the annular portion 142 of the coil end cover 104, large diameter portions 151 having a large diameter dimension (the dimension in the radial direction from the rotor axis center to the outer periphery) and small diameter portions 152 having a small diameter dimension are provided alternately in the circumferential direction at the portion axially facing the outer periphery covered portion 102. In this case, the wire 131 can be pulled from the outer periphery covered portion 102 side to the coil end cover 104 side without bulging in the radial direction while preventing the wire 131 from becoming unwound in the outer periphery covered portion 102. This makes it possible to suitably prevent the wire 131 from coming into contact with the stator 50.

[0070] In the rotor 60, winding units 110 are wound around each main pole portion 62 that extends radially from the axis of the rotor core 61. The rotor coil ends have a generally polygonal shape in plan view, with the number of angles corresponding to the number of magnetic poles. Therefore, in the annular portion 142 of the coil end cover 104, the radially outer side of the coil end of each winding unit 110 forms a flat portion that extends perpendicular to the extension direction of the main pole portion 62. The wire 131 of the outer covering portion 102 is pulled out in the axial direction from the flat portion of the coil end cover 104. In this case, the flat portion of the coil end cover 104 and the wire 131 intersect perpendicularly, which reduces the likelihood of the wire 131 being displaced in the circumferential direction. Furthermore, the radial dimension of the flat portion of the coil end cover 104 is partially reduced, which effectively prevents the wire 131 from contacting the stator 50.

[0071] In the outer covering portion 102, both ends (winding start end and winding end) of the wire 131 are pulled out to the same axial side and fixed to the same coil end cover 104. In other words, the winding start end and winding end end of the wire 131 are fixed to the same coil end cover 104. In this case, the structure for fixing the wire ends can be integrated into one coil end cover 104. Therefore, even when coil end covers 103, 104 are provided on both axial sides, it is only necessary to provide a fixing structure for the wire 131 to the coil end cover 104 on one side, which simplifies the design, etc.

[0072] The wire rod 131 is pulled out from the annular portion 142 to the end plate portion 141 in the coil end cover 104, and the wire rod tip portion 132 is fixed to the end plate portion 141 by welding. Furthermore, the bending angle of the wire rod 131 between the portion extending along the annular portion 142 and the portion extending along the end plate portion 141 is set to be 135° or less. In this case, a portion that receives stress due to bending can be provided between the outer circumferential coating portion 102 and the fixed portion of the tip of the wire rod 131. This makes it possible to reduce the load on the welded portion of the wire rod tip while minimizing the number of welded portions of the wire rod 131.

[0073] The coil ends of the field winding 70 are covered with coil end covers 104, and a coolant is circulated through the coil end covers 104. In this case, the wire 131 extending from the outer covering portion 102 is drawn from the annular portion 142 to the end plate portion 141 in the coil end cover 104, and the tip end of the wire is fixed to the end plate portion 141, so that the wire 131 is cooled by the coolant together with the coil end cover 104. This reduces thermal stress on the wire 131, and the wire 131 can be maintained in an appropriate state.

[0074] (Other embodiments) The above embodiment may be modified as follows, for example.

[0075] As shown in FIG. 17, the wire 131 may be pulled out in the axial direction along the annular portion 142 of the coil end cover 104 and fixed to the inclined surface 144 of the annular portion 142 by welding.

[0076] In the above embodiment, the outer peripheral surface of the annular portion 142 of the coil end cover 104 is configured as an inclined surface 144, and the annular portion 142 is provided with large diameter portions 151 and small diameter portions 152 alternating in the circumferential direction, but this may be modified. For example, the outer peripheral surface of the annular portion 142 of the coil end cover 104 may be configured to be parallel to the axial direction, and the annular portion 142 may be provided with large diameter portions 151 and small diameter portions 152 alternating in the circumferential direction. As above, the wire 131 may be configured to be pulled out in the axial direction from the small diameter portions 152. A small diameter portion may be formed on the outer peripheral portion of the coil end cover 103 on the circuit module 106 side, and the wire 131 may be configured to be pulled out in the axial direction from the small diameter portion.

[0077] In the stator 50, the stator core may not be provided with teeth.

[0078] The rotating electric machine is not limited to a rotating electric machine used as an in-vehicle main engine, but may also be, for example, a rotating electric machine used as an ISG (Integrated Starter Generator) which is a motor and generator.

[0079] The moving body on which the rotating electric machine system is mounted is not limited to a vehicle, but may be, for example, an aircraft or a ship. Furthermore, the rotating electric machine system is not limited to a system mounted on a moving body, but may be a stationary system.

[0080] The technical ideas extracted from the above-described embodiments will be described below. [Configuration 1] a rotor core (61) having a plurality of main pole portions (62) provided for each of the magnetic poles arranged in the circumferential direction; a field winding (70) provided around each of the main pole portions; an outer covering portion (102) formed by spirally winding a wire (131) around the radially outer side of each of the main pole portions and the field winding; a coil end cover (104) for covering a coil end of the field winding that is axially outward of the rotor core; A wound field rotor (60) comprising: the outer circumferential covering portion and the coil end cover are provided radially outside the field winding and continuously in the axial direction with their axial end faces facing each other, the wire is wound around the rotor core in the axial direction in an overlapping range in the radial direction, is pulled out in the axial direction along the outer peripheral surface of the coil end cover axially outside the outer peripheral covering portion, and is fixed to the coil end cover at a position radially inside the outer peripheral surface of the outer peripheral covering portion. [Configuration 2] the coil end cover has an end plate portion (141) that faces the coil end of the field winding in the axial direction, and an annular portion (142) that extends in the axial direction from an outer periphery of the end plate portion and surrounds the coil end of the field winding from the radially outer side, 2. The wound field rotor according to configuration 1, wherein the coil end cover has an inclined surface (144) formed on the outer circumferential side of the annular portion, the inclined surface being inclined with respect to the axial direction and approaching the rotor axis center on the side of the end plate portion, and the wire is drawn out in the axial direction along the inclined surface. [Configuration 3] the coil end cover has an end plate portion (141) that faces the coil end of the field winding in the axial direction, and an annular portion (142) that extends in the axial direction from an outer periphery of the end plate portion and surrounds the coil end of the field winding from the radially outer side, In the annular portion, a facing portion axially facing the outer peripheral covering portion is provided with large diameter portions (151) having a large radial dimension from the rotor axis center to the outer periphery and small diameter portions (152) having a small radial dimension alternately in the circumferential direction, 3. The wound field rotor according to configuration 1 or 2, wherein the wire is drawn out in the axial direction from the small diameter portion. [Configuration 4] In the rotor core, each of the main pole portions is provided so as to extend radially from the rotor axis, and a pole coil (110) is wound around each of the main pole portions as the field winding, The annular portion of the coil end cover has a flat portion extending in a direction perpendicular to the extension direction of the main pole portion on the radially outer side of the coil end of each pole coil, 4. The wound field rotor according to configuration 2 or 3, wherein the wire is drawn out in the axial direction from the flat portion. [Configuration 5] 5. The wound field rotor according to any one of configurations 1 to 4, wherein in the outer peripheral covering portion, both ends of the wire are pulled out to the same axial side and fixed to the same coil end cover. [Configuration 6] the coil end cover has an end plate portion (141) that faces the coil end of the field winding in the axial direction, and an annular portion (142) that extends in the axial direction from an outer periphery of the end plate portion and surrounds the coil end of the field winding from the radially outer side, the wire is drawn from the annular portion to the end plate portion of the coil end cover, and a tip end of the wire is fixed to the end plate portion by welding, 6. The wound field rotor according to any one of configurations 1 to 5, wherein the bending angle between the portion of the wire extending along the annular portion and the portion of the wire extending along the end plate portion is 135° or less. [Configuration 7] the coil end cover has an end plate portion (141) that faces the coil end of the field winding in the axial direction, and an annular portion (142) that extends in the axial direction from an outer periphery of the end plate portion and surrounds the coil end of the field winding from the radially outer side, In the coil end cover, an inlet (161) is provided in the end plate portion to allow a refrigerant to flow into a space between the coil end cover and a coil end of the field winding, and an outlet (162) is provided in the annular portion to allow the refrigerant to flow out of the space, The wound field rotor according to any one of configurations 1 to 6, wherein the wire is drawn from the annular portion to the end plate portion in the coil end cover, and a tip end of the wire is fixed to the end plate portion. [Explanation of symbols]

[0081] 60... rotor, 61... rotor core, 62... main pole portion, 70... field winding, 102... outer peripheral coating portion, 104... coil end cover, 131... wire material.

Claims

1. a rotor core (61) having a plurality of main pole portions (62) provided for each of the magnetic poles arranged in the circumferential direction; a field winding (70) provided around each of the main pole portions; an outer circumferential covering portion (102) formed by spirally winding a wire (131) around the radially outer sides of the main pole portions and the field winding; a coil end cover (104) for covering a coil end of the field winding that is axially outer than the rotor core; A wound field rotor (60) comprising: the outer circumferential covering portion and the coil end cover are provided radially outward of the field winding and are continuous in the axial direction with their axial end faces facing each other, the wire is wound around the rotor core in the axial direction in an overlapping range in the radial direction, is pulled out in the axial direction along the outer peripheral surface of the coil end cover axially outside the outer peripheral covering portion, and is fixed to the coil end cover at a position radially inside the outer peripheral surface of the outer peripheral covering portion.

2. the coil end cover has an end plate portion (141) that faces the coil end of the field winding in the axial direction, and an annular portion (142) that extends in the axial direction from an outer periphery of the end plate portion and surrounds the coil end of the field winding from the radially outer side, 2. The wound field rotor according to claim 1, wherein the coil end cover has an inclined surface (144) formed on an outer circumferential side of the annular portion, the inclined surface being inclined with respect to the axial direction and approaching the rotor axis center on the side of the end plate portion, and the wire is drawn out in the axial direction along the inclined surface.

3. the coil end cover has an end plate portion (141) that faces the coil end of the field winding in the axial direction, and an annular portion (142) that extends in the axial direction from an outer periphery of the end plate portion and surrounds the coil end of the field winding from the radially outer side, In the annular portion, a facing portion axially facing the outer peripheral covering portion is provided with large diameter portions (151) having a large radial dimension from the rotor axis center to the outer periphery and small diameter portions (152) having a small radial dimension alternately in the circumferential direction, 2. The wound field rotor according to claim 1, wherein said wire is drawn out in the axial direction from said small diameter portion.

4. In the rotor core, each of the main pole portions is provided so as to extend radially from the rotor axis, and a pole coil (110) is wound around each of the main pole portions as the field winding, The annular portion of the coil end cover has a flat portion extending in a direction perpendicular to the extension direction of the main pole portion on the radially outer side of the coil end of each pole coil, 4. The wound field rotor according to claim 2, wherein the wire is drawn out in the axial direction from the flat portion.

5. 2. The wound field rotor according to claim 1, wherein both ends of the wire in the outer peripheral covering portion are pulled out to the same axial side and fixed to the same coil end cover.

6. the coil end cover has an end plate portion (141) that faces the coil end of the field winding in the axial direction, and an annular portion (142) that extends in the axial direction from an outer periphery of the end plate portion and surrounds the coil end of the field winding from the radially outer side, the wire is drawn from the annular portion to the end plate portion of the coil end cover, and a tip end of the wire is fixed to the end plate portion by welding, 2. The wound field rotor according to claim 1, wherein a bending angle between a portion of the wire extending along the annular portion and a portion of the wire extending along the end plate portion is 135° or less.

7. the coil end cover has an end plate portion (141) that faces the coil end of the field winding in the axial direction, and an annular portion (142) that extends in the axial direction from an outer periphery of the end plate portion and surrounds the coil end of the field winding from the radially outer side, In the coil end cover, an inlet (161) is provided in the end plate portion to allow a refrigerant to flow into a space between the coil end cover and the coil end of the field winding, and an outlet (162) is provided in the annular portion to allow the refrigerant to flow out of the space, 2. The wound field rotor according to claim 1, wherein the wire is drawn from the annular portion to the end plate portion of the coil end cover, and a tip end of the wire is fixed to the end plate portion.

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