Electric rotary machine

Abstract

Electric rotary machine with a rotor (5, 5A, 5B, 5C) connected to a crankshaft (50) of an internal combustion engine, such that it is set in rotation by a mechanical power from the internal combustion engine, wherein: the rotor (5, 5A, 5B, 5C) has: a cylindrical rotor core (6) produced by laminating electromagnetic steel disks to have a cylindrical shape, Magnets (7), and a rotor core (10, 10A, 10C, 40) with: a cylindrical rotor ring (11, 11C) that holds the rotor core (6), a ring-shaped mounting section (12) which is connected to the crankshaft (50) in such a way that it is provided coaxially at a first axial end inside the rotor ring (11, 11C), and a connecting plate (13, 13A) which connects the rotor ring (11, 11C) and the mounting section (12), and wherein the connecting plate (13, 13A) is designed to have a curved shape that is convex towards a first axial end or a second axial end of the rotor hub (10, 10A, 10C, 40) and where the connecting plate (13, 13A) has a thickness that decreases continuously or discontinuously from a radially inner side to a radially outer side or from a radially outer side to a radially inner side, the magnets (7) are each received in several magnet receiving openings (8) which are designed circumferentially such that they pass axially through an outer circumferential side of the rotor core (6), wherein the magnets (7) are attached to the rotor core (6) using an adhesive (9), wherein the connecting plate (13A) has: a ring-shaped flat plate section (32) having a constant thickness, wherein the ring-shaped flat plate section (32) is provided at an intermediate position between the mounting section (12) and the rotor ring (11), a radially inner curved section (30) connecting the mounting section (12) and the annular flat plate section (32), which has a thickness that continuously increases or decreases from the radially inner side to the radially outer side, so that it becomes equal to the thickness of the annular flat plate section (32), and a radially outer curved section (31) which connects the rotor ring (11) and the annular flat plate section (32), which has a thickness that continuously increases or decreases from the radially outer side to the radially inner side, so that it becomes equal to the thickness of the annular flat plate section (32).

Description

Technical area

[0001] The present invention relates to an electric rotary machine provided in series with a torque converter between a crankshaft of an internal combustion engine and a main shaft of a transmission and transmitting mechanical power from the internal combustion engine to the transmission, and more particularly relates to a rotor hub structure capable of achieving reductions in rigidity and stress distribution in a rotor hub. State of the art

[0002] In ordinary mechanical power transmission devices in hybrid vehicles, a converter and a torque converter are connected in series between a crankshaft of an internal combustion engine and a main shaft of a transmission, and charge a battery and perform energy recovery through regenerative braking by the converter acting as a generator, and start the internal combustion engine and assist the internal combustion engine power by the converter acting as a motor (see, for example, Patent Document 1).

[0003] However, in the conventional hybrid power transmission device described in Patent Document 1, since the engine, inverter, and torque converter are arranged in series in a straight line, the direct distance from the engine to the torque converter is long. Thus, the loads acting on the torque converter from the engine, especially the bending moment loads, are increased, and there is a risk of damage to the torque converter.

[0004] In view of such conditions, conventional mechanical power transmission devices in hybrid vehicles have been proposed, in which a torque converter is provided within a rotor of a converter (see, for example, Patent Document 2). In the conventional mechanical power transmission device in hybrid vehicles described in Patent Document 2, since the direct distance from the internal combustion engine to the torque converter can be reduced, loads acting on the torque converter from the internal combustion engine are reduced, suppressing the occurrence of damage to the torque converter. Citation listPatent literature Patent Document 1: Japanese Patent Application Laid-Open No. JP H05-30605A Patent Document 2: Japanese Patent Application Laid-Open No. JP 2003-70207A

[0005] DE 101 28 424 A1 discloses features falling under the preamble of claim 1. US 2011 / 0 012 448 A1 is further prior art. Description of the invention Problem to be solved by the invention

[0006] However, in the conventional mechanical power transmission device in hybrid vehicles described in Patent Document 2, since the torque converter is provided in the rotor of the converter, there has been a problem that radial dimensions of the rotor are increased, which increases the size of the converter.

[0007] The present invention aims to solve the above problems, and it is an object of the present invention to provide an electric rotary machine that suppresses the occurrence of damage to a torque converter while suppressing increases in the radial dimensions of a rotor in a configuration in which the rotor and the torque converter are connected in series between a crankshaft of an internal combustion engine and a main shaft of a transmission, by absorbing loads resulting from the internal combustion engine using a rotor hub to reduce loads acting on the torque converter. Means of solving the problem

[0008] The invention is defined by claim 1. Effects of the invention

[0009] According to the present invention, since the thickness of the connecting plate decreases continuously or discontinuously from the radially inner side to the radially outer side or from the radially outer side to the radially inner side, a side of the connecting plate near the rotor ring or a side near the attachment portion forms a thinnest portion. When loads originating from the internal combustion engine act on the rotor hub, the thinnest portion of the connecting plate deforms and absorbs the respective forces. Thus, when the rotor of the present electric rotary machine and a torque converter are provided in series between the crankshaft of the internal combustion engine and a main shaft of a transmission, the loads originating from the internal combustion engine are absorbed by the deformation of the thinnest portion of the connecting plate, reducing the loads transmitted to the torque converter side.Thus, it is not necessary to provide the torque converter inside the rotor, which allows increases in the outer diameter dimensions of the rotor to be suppressed.

[0010] Since the connecting plate is formed to have a curved shape convex toward the first axial end or the second end of the rotor hub, stresses concentrated at a connecting portion between the connecting plate and the rotor ring and at a connecting portion between the connecting plate and the attachment portion are dispersed, which enables the fatigue strength to be increased. Short description of the drawings Fig. 1 is a half-section showing a converter according to Example 1, which does not fall under claim 1, Fig. 2 is a diagram showing a manufacturing process for a rotor hub in the converter according to Example 1, Fig. 3 is a half-sectional view showing a rotor of a converter according to Embodiment 1 of the present invention, Fig. Fig. 4 is a half-section showing a rotor of a converter according to Example 2 not falling under claim 1, Fig. Fig. 5 is a half-section showing a rotor of a converter according to Example 4 not falling under claim 1, and Fig. 6 is a diagram showing a manufacturing method of a rotor hub used for a rotor of a converter according to Example 5 of the present invention, which does not fall under claim 1. Description of the embodiments

[0011] Preferred embodiments of an electric rotary machine according to the present invention will be explained with reference to the drawings. Example 1

[0012] Fig. 1 is a half-section showing a converter according to Example 1, and Fig. 2 is a diagram showing a manufacturing method for a rotor hub in the converter according to Example 1.

[0013] In Fig. 1, an inverter 100 serving as an electric rotary machine includes: a stator 1, a rotor 5 provided inside the stator 1 so as to be coaxial with the stator 1, and a sensor portion 20 that detects a rotational speed of the rotor 5.

[0014] The stator 1 includes a ring-shaped stator core 2 and a stator coil 3 attached to the stator core 2. The stator core 2 is made by laminating and joining electromagnetic steel discs and is inserted into a cylindrical iron frame 4 to be held by press fitting or shrinking.

[0015] The rotor 5 includes a cylindrical rotor core 6 having a smaller diameter than the stator core 2, permanent magnets 7 attached to the stator core 6 to form magnetic poles, and a rotor hub 10 that supports the rotor core 6. The rotor core 6 is made by laminating and uniting electromagnetic steel discs punched into an annular shape. A plurality of magnet receiving holes 8 are each formed in the rotor core 6 at a uniform angular pitch along the circumference to axially pass through the rotor core 6. The permanent magnets 7 are inserted into all the magnet receiving holes 8 and fixed to the rotor core 6 using adhesive 9.

[0016] The rotor hub 10 is manufactured using a ferrous material and includes: a cylindrical rotor ring 11 that holds the rotor core 6, an annular attachment portion 12 that is provided coaxially inside a first axial end of the rotor ring 11 and that is fixed to the crankshaft 50 by screws, and a connecting plate 13 that is formed to extend radially outward from a second end edge portion of the attachment portion 12 to a first end of an inner peripheral surface of the rotor ring 11 and connects the rotor ring 11 and the attachment portion 12.

[0017] The rotor ring 11 includes a cylindrical portion 11a having a constant thickness, such as a thickness of 4 mm, and a positioning flange portion 11b formed to radially protrude around an entire circumference at a second end of an outer peripheral surface of the cylindrical portion 11a. A cross-sectional shape of the connecting plate 13, which has a central axis of the rotor hub 10, is a curved shape convex toward a second axial end of the rotor hub 10 and a thickness of which decreases continuously from a radially inner side to a radially outer side.Specifically, the cross-sectional shape of the connecting plate 13, which has the central axis of the rotor hub 10, is a circular arc defined by a circular arc having a first radius of curvature and a circular arc having a second radius of curvature larger than the first radius of curvature, and one end thereof is thinnest near the rotor ring 11. Here, a thickness at a thinnest portion A is less than 4 mm.

[0018] The sensor section 20 includes an annular sensor plate 21 and a sensor wheel 22 fixed to an outer peripheral portion of the sensor plate 21. A press-fit nut 23 is press-fitted into and held by the sensor plate 21.

[0019] To assemble the rotor 5, the permanent magnets 7 are first inserted into each of the magnet receiving holes 8, and the permanent magnets 7 are fixed to the rotor core 6 using the adhesive 9. Next, end plates 14 and 15, which are punched from a non-magnetic metal sheet into an annular shape having an inner diameter the same as an inner diameter of the rotor core 6, are provided at two axial ends of the rotor core 6, and the rotor core 6 is press-fitted onto the cylindrical portion 11a of the rotor ring 11 from a first axial end until the end plate 14 is brought into contact with the positioning flange portion 11b. Thus, the rotor 5 is assembled. Next, the annular sensor plate 21 is placed over the cylindrical portion 11a of the rotor ring 11 from a second axial end to come into contact with the positioning flange portion 11b, and is fixed to the rotor ring 11 by welding.The number 24 indicates the welding section.

[0020] In the thus-assembled rotor 5, the end plates 14 and 15 are manufactured to have outer diameter dimensions that cover the magnet receiving holes 8 and prevent scattering of the permanent magnets 7. The axial position of the rotor core 6 is also ensured with high precision by positioning the end plate 14 in contact with the positioning flange portion 11b. In addition, the circumferential movement and axial movement of the rotor core 6 are limited by press-fitting the laminated body including the rotor core 6 and the end plates 14 and 15 to the cylindrical portion 11a of the rotor ring 11.

[0021] In addition, when the ambient temperature of the converter 100 becomes high, the press-fitting fastening force of the rotor core 6 and the end plates 14 and 15 is reduced, and there is a risk that the rotor core 6 and the end plates 14 and 15 cannot rotate together with the rotor ring 11 during high-speed rotation of the rotor 5. Therefore, it is desirable to reliably restrict the circumferential movement of the rotor core 6 by forming key portions projecting radially inward on an inner peripheral surface of the laminated body including the rotor core 6 and the end plates 14 and 15 so as to extend from the first axial end to the second axial end, by recessing keyways extending axially into an outer peripheral surface of the cylindrical portion 11a of the rotor ring 11, and fitting the key portions together with the keyways during press-fitting of the rotor core 6.

[0022] A manufacturing method for the rotor hub 10 will now be described with reference to Fig. 2 will be explained.

[0023] As in Fig. 2A shows a rotor hub precursor 18 comprising a rotor ring 11, an attachment portion 12, and a connecting plate 13' connecting a second outer peripheral end portion of the attachment portion 12 and a first end portion of an inner peripheral surface of the rotor ring 11. This connecting plate 13' is first manufactured by machining a blank produced, for example, by hot forming. Furthermore, the connecting plate 13' is formed into an annular flat plate in which a thickness continuously decreases from a radially inner side to a radially outer side, which is provided so as to be perpendicular to a central axis of the rotor ring 11 and to cover it between the rotor ring 11 and the attachment portion 12. Thereafter, as shown in Fig. 2B, the connecting plate 13' is formed by press working to have a curved shape convex toward a second axial end of the rotor ring 11 to manufacture the rotor hub 10.

[0024] As in Fig. As shown in Figure 1, the mounting portion 12 of the rotor hub 10 of the converter 100 is connected to the crankshaft 50 of an internal combustion engine (not shown) by bolts (not shown). Additionally, the torque converter 51 is connected to the sensor plate 21 by fastening a bolt 52 to the press-in nut 23 to form a device for transmitting mechanical power from a motor vehicle. The rotor 5 and the torque converter 51 of the converter 100 are thus provided rectilinearly between the crankshaft 50 of the internal combustion engine and the main shaft 53 of a transmission.

[0025] In the mechanical power transmission device configured in this way, when the internal combustion engine is operating, mechanical power from the internal combustion engine is input to the torque converter 51 via the crankshaft 50 and the rotor hub 10. Thus, the mechanical power of the internal combustion engine is amplified by the conversion operation of the torque converter 51 and is transmitted to the main shaft 53 of the transmission. By causing the converter 100 to act as a generator, a battery is charged or energy recovery is performed through regenerative braking. By causing the converter 100 to act as a motor, the internal combustion engine is started or the output of the internal combustion engine is assisted.

[0026] According to Example 1, since the connecting plate 13 is formed to have a circular arc-shaped cross section in which a thickness continuously decreases from a radially inner side to a radially outer side, a vicinity of a connecting portion of the connecting plate 13 with the cylindrical portion 11a of the rotor ring 11 becomes a thinnest portion A with low rigidity. Thus, when axial loads and bending moments generated in cylinders of the internal combustion engine during detonation act on the rotor hub 10 via the crankshaft 50, these loads originating from the internal combustion engine are not transmitted to the torque converter 51 because the thinnest portion A of the connecting plate 13 deforms.Accordingly, even if the rotor 5 and the torque converter 51 of the converter 100 are provided in a straight line between the crankshaft 50 of the internal combustion engine and the main shaft 53 of the transmission, loads acting on the torque converter 51 from the internal combustion engine are reduced. Therefore, the need to house the torque converter 51 within the rotor 5 is avoided, making it possible to reduce the radial dimensions of the rotor 5. The occurrence of damage to the torque converter 51 is also suppressed, thereby reducing losses due to failures.

[0027] Since the connecting plate 13 is formed to have a curved shape convex toward the second axial end in which the thickness continuously decreases from a radially inner side to a radially outer side, stresses concentrated at connecting portions between the connecting plate 13 and the cylindrical portion 11a of the rotor ring 11 and at connecting portions between the connecting plate 13 and the attachment portion 12 are reduced.Specifically, stresses occurring at a joint portion between a surface of the connecting plate 13 facing the first axial end and the cylindrical portion 11a of the rotor ring 11, a joint portion between a surface of the connecting plate 13 facing the second axial end and the cylindrical portion 11a of the rotor ring 11, a joint portion between a surface of the connecting plate 13 facing the first axial end and the attachment portion 12, and a joint portion between a surface of the connecting plate 13 facing the second axial end and the attachment portion 12 are dissipated.Thus, stress concentrations at the connecting portions between the connecting plate 13 and the cylindrical portion 11a of the rotor ring 11 and the connecting portions between the connecting plate 13 and the attachment portion 12 are alleviated, thereby increasing fatigue strength. Heat treatment of the thinnest portion A of the connecting plate 13 is thus no longer required, thereby reducing the machining costs of the rotor hub 10.

[0028] Furthermore, in Example 1 above, the rotor core 6 is press-fitted onto the cylindrical portion 11a of the rotor ring 11, but the rotor core 6 may also be loosely fitted onto the cylindrical portion 11a of the rotor ring 11. In this case, it is necessary to restrict the circumferential movement and the axial movement of the rotor core 6.Methods for restricting movement along the circumference of the rotor core 6 include, for example, methods in which key portions projecting radially inward on an inner peripheral surface of the laminated body comprising the rotor core 5 and end plates 14 and 15 are formed to extend from the first axial end to the second axial end, keyways extending axially are formed to be recessed in an outer peripheral surface of the cylindrical portion 11a of the rotor ring 11, and the key portions are fitted into the keyways during press-fitting of the rotor core 6. Methods for restricting the axial movement of the rotor core 6 include, for example, methods in which a first axial end of the rotor ring 11 is caulked.Here, the keyways may be formed on the inner peripheral surface of the laminated body having the rotor core 6 and the end plates 14 and 15, and key portions may be formed on the outer peripheral surface of the cylindrical portion 11a.

[0029] In the above Example 1, the rotor core 6 is held on the cylindrical portion 11a of the rotor ring 11 by press fitting, but the rotor core 6 may also be held on the cylindrical portion 11a of the rotor ring 11 by shrink fitting.

[0030] In the above Example 1, the connecting plate 13 is manufactured by pressing to have a curved shape, but the connecting plate 13 may also be manufactured by machining to have a curved shape.

[0031] In the above Example 1, the positioning flange portion 11b is formed on the outer peripheral surface of the cylindrical portion 11a continuously around a circumference of a common circle, but positioning flange portions may also be formed on the outer peripheral surface of the cylindrical portion 11a discontinuously around the circumference of a common circle. Embodiment 2

[0032] Fig. 3 is a half-sectional view showing a rotor of a converter according to Embodiment 2 of the present invention.

[0033] In Fig. 3 includes a rotor hub 10A: a rotor ring 11, a mounting portion 12, and a connecting plate 13A connecting the rotor ring 11 and the mounting portion 12. The connecting plate 13A is formed to extend radially outward from a second end edge portion of the mounting portion 12 while continuously decreasing in thickness, and then extend radially outward while maintaining the same thickness, and then extend radially outward while continuously decreasing in thickness to reach an inner peripheral surface of a cylindrical portion 11a of the rotor ring 11.

[0034] In addition, the rest of the configuration is formed in a similar or identical manner to that of Example 1 above.

[0035] The rotor 5A is configured in a similar or identical manner to the rotor 5, except that the rotor hub 10A is used instead of the rotor hub 10. The connecting plate 13A of the rotor hub 10A is formed by: a radially inner curved portion 30 having a circular arc-shaped cross section whose thickness continuously decreases from a radially inner side to a radially outer side; and an annular flat plate portion 32 having a constant thickness connecting the radially inner curved portion 30 and the radially outer curved portion 31. In other words, the thickness of the connecting plate 13A decreases discontinuously from a radially inner side to a radially outer side. The annular flat plate portion 32 is perpendicular to a central axis of the rotor hub 10A.Further, a thinnest portion A is on the radially outer curved portion 31 in a vicinity of the rotor ring 11. A cross-sectional shape of the connecting plate 13A including a central axis of the rotor hub 10A is a curved shape convex toward a second axial end of the rotor hub 10A.

[0036] In Embodiment 2, the cross-sectional shape of the connecting plate 13A, which has the central axis of the rotor hub 10A, is a curved shape convex toward the second axial end of the rotor hub 10A, the thicknesses of the radially inner curved portion 30 and the radially outer curved portion 31 are formed to continuously decrease from the radially inner side to the radially outer side, and the thinnest portion A on the radially outer curved portion 31 is in the vicinity of the rotor ring 11. Accordingly, similar or identical effects to those of Example 1 are also achieved in Embodiment 2.

[0037] Now, there is reproducibility in the movement of the machining tool, and the shape (dimensions) of the radially inner curved portion 30 and the radially outer curved portion 31 of the connecting plate 13A are fixed when determining the axial height of the connecting plate 13A. Since the radially inner curved portion 30 and the radially outer curved portion 31 of the connecting plate 13A have curved shapes, the dimensions of the radially inner curved portion 30 and the radially outer curved portion 31 cannot be easily measured.

[0038] According to Embodiment 2, a radially central portion of the connecting plate 13A is formed into an annular flat plate portion 32 perpendicular to the central axis of the rotor hub 10A. In other words, since the radially central portion of the connecting plate 13A is a flat surface perpendicular to the central axis of the rotor hub 10A, the axial height of the connecting plate 13A from the rotor hub 10A can be easily and accurately measured. The dimensions of the radially inner curved portion 30 and the radially outer curved portion 31 can also be controlled by controlling the axial height of the connecting plate 13A from the rotor hub 10A.Thus, since steps for measuring the dimensions of the radially inner curved portion 30 and the radially outer curved portion 31, which are difficult to measure after the rotor hub 10A is formed, can be omitted, the cost for the dimensional inspection is reduced, enabling a cost reduction for the rotor hub 10A to be achieved. Embodiment 3

[0039] Fig. 4 is a half-sectional view showing a rotor of a converter according to Embodiment 3 of the present invention.

[0040] In Fig. 4, end plates 14 and 15 are omitted from a rotor 5B and only a rotor core 6 is fitted over a rotor ring 11 and held by a cylindrical portion 11a.

[0041] In particular, the rest of the design is similar or identical to Example 1 above.

[0042] In Embodiment 3, since the rotor hub 10 is used, similar effects to those in the above Example 1 can be achieved. Since the permanent magnets 7 are fixed to the rotor core 6 using adhesive 9 in the rotor 5B, situations where the permanent magnets 7 are scattered during rotation of the rotor 5B are avoided.

[0043] According to Embodiment 3, end plates 14 and 15 are omitted, and only one rotor core 6 is held by fitting it over the cylindrical portion 11a of the rotor ring 11. Thus, since the number of components is reduced, component costs can be reduced, and weight is also reduced, which reduces the moment of inertia. Embodiment 4

[0044] Fig. 5 is a half-sectional view showing a rotor of a converter according to Embodiment 4 of the present invention.

[0045] In Fig. 5, a rotor hub 10C includes a rotor ring 11C, a mounting portion 12, and a connecting plate 13 connecting a first end portion of an inner peripheral surface of the rotor ring 11C and a second outer peripheral end edge portion of the mounting portion 12. The rotor ring 11C includes a cylindrical portion 11a, a positioning flange portion 11b formed on a second side of an outer peripheral surface of the cylindrical portion 11a, and a caulking flange portion 11c functioning as a caulking portion formed to have a cylindrical shape having an outer diameter equal to the cylindrical portion 11a and a thickness thinner than the cylindrical portion 11, and coaxially protruding from a first end surface of the cylindrical portion 11a.

[0046] The rotor core 6 is press-fitted onto the cylindrical portion 11a of the rotor ring 11C from a first axial end until it contacts the positioning flange portion 11b. Additionally, an end plate 16, which has an outer diameter dimension that does not cover the magnet housing openings 8, is press-fitted onto the cylindrical portion 11a of the rotor ring 11C from a first axial end until it contacts a first axial end surface of the rotor core 6. Additionally, the caulking flange portion 11c is caulked radially outward to assemble the rotor 5C.

[0047] In addition, the rest of the design is similar or identical to that of Example 1 above.

[0048] In Embodiment 4, a caulking force from the caulking flange portion 11c acts to press the rotor core 6 against the positioning flange portion 11b via the end plate 16. The end plate 16 and the rotor core 6 are thereby pressed and held between the positioning flange portion 11b and the caulking flange portion 11c, thereby greatly restricting the axial movement of the rotor core 6. Since the permanent magnets 7 are fixed to the rotor core 6 using the adhesive 9 in the rotor 5C, situations such as the permanent magnets 7 being scattered during rotation of the rotor 5C are avoided.

[0049] Now, if the end plate 16 is designed to have an outer diameter dimension that covers the magnet housing openings 8, it is necessary to manufacture the end plate 16 using a non-magnetic material. Accordingly, the thermal expansion coefficients of the end plate 16 and the rotor hub 10 are different, which reduces the press-fitting fastening force of the end plate 16 as the ambient temperature increases.

[0050] In Embodiment 4, since the end plate 16 is formed to have an outer diameter dimension that does not cover the magnet housing openings 8, the end plate 16 can be manufactured using a magnetic material similar to or identical to that of the rotor hub 10C. Thus, the thermal expansion coefficients of the end plate 16 and the rotor hub 10 are identical, thereby suppressing reductions in the press-fitting fastening force of the end plate 16 even when the ambient temperature increases.

[0051] Since the end plate 15 is omitted in the above Example 1 and an end plate 16 having a smaller outer diameter dimension is used instead of the end plate 14, a reduction in component costs can be achieved.

[0052] Furthermore, in Embodiment 5, the circumferential movement of the rotor core 6 and the end plate 4 can also be restricted by forming key portions projecting radially inward on an inner circumferential surface of the rotor core 6 and the end plate 16 so as to extend from the first axial end to the second axial end, by recessing keyways extending axially in an outer circumferential surface of the cylindrical portion 11a of the rotor ring 11, and fitting the key portions into the keyways during press-fitting of the rotor core 6 and the end plate 16. Embodiment 5

[0053] Fig. 6 is a diagram explaining a manufacturing method of a rotor hub used in a rotor of a converter according to Embodiment 5 of the present invention.

[0054] In the manufacturing method for a rotor hub according to embodiment 5, as in Fig. 6A, a radially outer part 41 in which a positioning flange portion 43 is formed at a second axial end of an outer peripheral surface of a cylindrical portion 42, and a radially inner part 45 in which an annular attachment portion 46 is integrally formed on an inner peripheral edge of a connecting plate 47, in which an annular flat plate having a thickness that continuously decreases from a radially inner side to a radially outer side is formed to have a curved shape in a second axial direction, is first manufactured. Thereafter, as in Fig.6B, a rotor hub 40 is manufactured by welding an outer peripheral edge of the connecting plate 47 to the first axial end of an inner peripheral surface of the cylindrical portion 42 to connect the radially outer part 41 and the radially inner part 45. Here, numeral 48 denotes the welding portion.

[0055] According to Embodiment 5, since a radially outer part 41 corresponding to a rotor ring and a radially inner part 45 in which an attachment portion 46 and a connecting plate 47 are formed together are prepared, and then a rotor hub 40 is manufactured by joining the radially outer part 41 and the radially inner part 45 by welding, options for methods of machining the cylindrical part 42 (the rotor ring), the attachment portion 46, and the connecting plate 47 are increased. Thus, an optimal machining method can be selected for each of the parts, making it possible to reduce costs. Furthermore, a blank can be manufactured by roll forging instead of hot working, which increases productivity and also makes it possible to increase the material yield.

[0056] In addition, in each of the above embodiments and examples, a connecting plate is formed to have a thickness that continuously decreases from a radially inner side to a radially outer side, but a connecting plate may also be formed to have a thickness that continuously decreases from a radially outer side to a radially inner side.

[0057] In each of the above embodiments and examples, a connecting plate is formed to have a curved shape convex toward a second axial end of a rotor hub, but a connecting plate may also be formed to have a curved shape convex toward a first axial end of a rotor hub.

Claims

[1] An electric rotary machine comprising a rotor (5, 5A, 5B, 5C) connected to a crankshaft (50) of an internal combustion engine so as to be rotated by a mechanical power from the internal combustion engine, wherein: the rotor (5, 5A, 5B, 5C) has: a cylindrical rotor core (6) made by laminating electromagnetic steel discs to have a cylindrical shape, Magnets (7), and a rotor core (10, 10A, 10C, 40) with: a cylindrical rotor ring (11, 11C) holding the rotor core (6), an annular mounting portion (12) connected to the crankshaft (50) so as to be coaxially provided at a first axial end within the rotor ring (11, 11C), and a connecting plate (13, 13A) connecting the rotor ring (11, 11C) and the mounting portion (12), and wherein the connecting plate (13, 13A) is formed to have a curved shape which is convex towards a first axial end or a second axial end of the rotor hub (10, 10A, 10C, 40) and where the connecting plate (13, 13A) has a thickness which decreases continuously or discontinuously from a radially inner side to a radially outer side or from the radially outer side to the radially inner side, the magnets (7) are each received in a plurality of magnet receiving holes (8) which are circumferentially formed so as to pass axially through an outer peripheral side of the rotor core (6), wherein the magnets (7) are fixed to the rotor core (6) using an adhesive (9), wherein the connecting plate (13A) comprises: an annular flat plate portion (32) having a constant thickness, the annular flat plate portion (32) being provided at an intermediate position between the mounting portion (12) and the rotor ring (11), a radially inner curved portion (30) connecting the attachment portion (12) and the annular flat plate portion (32), which has a thickness that continuously increases or decreases from the radially inner side to the radially outer side so that it becomes equal to the thickness of the annular flat plate portion (32), and a radially outer curved portion (31) connecting the rotor ring (11) and the annular flat plate portion (32) having a thickness that continuously increases or decreases from the radially outer side to the radially inner side so as to become equal to the thickness of the annular flat plate portion (32). [2] Electric rotary machine according to claim 1, wherein the rotor hub (40) comprises: a radially inner part (45) in which the attachment portion (46) and the connecting plate (47) are integrally formed, and a radially outer part (41) formed by the rotor ring, wherein the rotor hub (40) is formed by joining the connecting plate (47) and the rotor ring (41) by welding. [3] The rotary electric machine according to any one of claims 1 to 2, wherein the connecting plate (13) is formed by pressing to have a curved shape. [4] Electric rotary machine according to one of claims 1 to 3, wherein: a positioning flange portion (11b, 43) is formed on a second axial side of an outer peripheral surface of the rotor ring (11, 11C, 41) and the rotor core (6) is held by fitting over the rotor ring (11, 11C, 41) so that it is in contact with the positioning flange portion (11b, 43). [5] Electric rotary machine according to claim 4, wherein only the rotor core (6) is held by the rotor ring (11). [6] An electric rotary machine according to claim 4, wherein: an end plate (16) is mounted so as to fit over the rotor ring (11C) so as to be positioned radially inside the magnet receiving openings (8) and so as to contact a first axial end surface of the rotor core (6) and the end plate (16) and the rotor core (6) are pressed and held between a radially outwardly directed caulking portion (11c) at a first axial end portion of the rotor ring (11C) and the positioning flange portion (11b) so that the axial movement is restricted.

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