JP2014230294A - Rotor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotor capable of reducing cost and securing a sufficient space for accommodating other components.SOLUTION: An inner circumferential part 30 includes a fitting surface 22 to be fitted with a rotary shaft 16 and is produced by hammering. An outer circumferential part 32 is press-molded and includes an outer circumferential surface 24 (cylindrical outer surface) to which a rotor core 18 is fixed, and a hollow disc portion 26 connected to an axial annular end of the outer circumferential surface 24 and formed integrally with the outer circumferential surface 24. The inner circumferential part 30 and the outer circumferential part 32 are bonded by welding in coupling portions 34 which are formed in an inner circumferential-side end of the disc portion 26 of the outer circumferential part 32 and an outer circumferential-side end of the inner circumferential part 30, thereby producing a holding member 20.

Description

  The present invention relates to a rotor used in a motor or a generator, and relates to a rotor suitable for application to an electric vehicle such as a hybrid vehicle or a fuel cell vehicle.

  Conventionally, as shown in FIG. 8, an outer cylinder member 204 that holds the rotor core 202 on the outer peripheral surface and an inner cylinder member 206 to which a rotation shaft (not shown) is fixed on the inner peripheral surface are provided. A structure of a rotor hub 200 in which a cylindrical member 206 is integrated is proposed (Patent Document 1). In the rotor hub 200, a flange portion 208 is formed at an intermediate portion in the axial direction of the inner cylinder member 206. By pressing the inner cylinder member 206 into the outer cylinder member 204 from the direction of the arrow so that the tooth forming part 210 on the outer peripheral surface of the flange part 208 and the tooth forming part 212 on the inner peripheral surface of the outer cylinder member 204 are aligned, An integrated rotor hub 200 is formed.

  Here, the inner cylinder member 206 whose inner peripheral surface is fitted to a rotating shaft (not shown) is subjected to carburizing and quenching to increase the hardness after cold forging, while the outer cylinder member 204 is manufactured by sheet metal pressing. Has been.

  Patent Document 1 describes that the cost of the rotor hub 200 can be reduced by manufacturing in this way.

JP 2011-205807 A (FIG. 8, [0051], [0052], [0053], [0062])

  However, as a result of the flange portion 208 being formed in the inner cylinder member 206 disclosed in Patent Document 1, the surface area of the inner cylinder member 206 is relatively large. For this reason, post-processing time such as descaling and shaving after forging takes a long time, and the processing cost increases accordingly. Further, since the flange portion 208 is formed, the material cost for forging increases accordingly. Further, since the flange portion 208 is formed at a substantially intermediate portion in the axial direction of the inner cylinder member 206, a space formed between the inner circumferential surface of the outer cylinder member 204 and the outer circumferential surface of the inner cylinder member 206. Is divided into two, and a sufficient space for accommodating other parts cannot be secured.

  The present invention has been made in consideration of such problems, and an object of the present invention is to provide a rotor capable of reducing the cost and securing a sufficient space for accommodating other components. And

  The rotor according to the present invention is a rotor including a rotating shaft and a holding member that is formed separately from the rotating shaft, is fixed to the rotating shaft, and holds a rotor core on the outer periphery. Is configured in a cylindrical shape and fitted to the rotating shaft; an outer peripheral surface (cylindrical outer surface) configured in a cylindrical shape to which the rotor core is fixed; and an annular end in the axial direction of the outer peripheral surface A hollow disk-shaped disk part that is connected to a part and formed integrally with the outer peripheral surface, and the holding member includes an inner peripheral part including the fitting surface, and the outer peripheral surface and the disk part. The outer peripheral part is configured to be coupled at the coupling part, and the coupling part is formed at an inner peripheral side end of the disk part and an outer peripheral side end of the inner peripheral part.

  According to this invention, the inner peripheral portion including the fitting surface fitted to the rotating shaft, the outer peripheral surface to which the rotor core is fixed, and the annular end portion in the axial direction of the outer peripheral surface are connected and integrated with the outer peripheral surface. The outer peripheral portion having a hollow disc portion formed on the outer peripheral portion is coupled and held by the coupling portions respectively formed on the inner peripheral side end portion of the outer peripheral portion and the outer peripheral side end portion of the inner peripheral portion. Since the member is formed, it becomes easy to manufacture a holding member having a configuration in which two parts (inner peripheral portion and outer peripheral portion) having simple shapes are combined, and the cost can be reduced. In addition, since the disk portion connected to the annular end portion in the axial direction of the outer peripheral surface is integrally formed, a sufficient space can be secured between the rotating shaft and the outer peripheral surface.

  For example, the inner peripheral part is formed of a forged product that satisfies requirements such as accuracy, strength, and hardness in order to transmit torque to the rotating shaft, and the outer peripheral part is a press-formed product (drawing process) that minimizes the processing man-hours. Product).

  Here, the outer peripheral portion includes an axial protruding portion that protrudes outward in a direction opposite to the outer peripheral surface side with respect to the axial direction at the inner peripheral end portion of the disk portion, and the axial protruding portion. Since the rotation sensor for detecting the rotation angle of the rotor is fixed to the part, a separate member for fixing the rotation sensor becomes unnecessary, and an increase in cost can be suppressed.

  Furthermore, an abutting surface provided in a direction orthogonal to the axial direction and a first fitting portion that forms a fitting portion in the axial direction are formed at the inner peripheral side end of the disk portion, An abutting surface that is abutted against the abutting surface and a second fitting portion that fits into the first fitting portion are formed at the outer peripheral side end of the inner circumferential portion, and the first fitting portion In the state where the abutment surface of the second fitting portion is abutted against the abutting surface, the mouth portions of the first fitting portion and the second fitting portion are smoothed and smoothed. In this state, the first fitting portion and the second fitting portion are joined by welding from the mouth portion side, so that the abutting surface located on the farthest side as viewed from the mouth portion during welding is in contact with the abutting surface. Since the contact surface is abutted, spatter scattering is prevented and the mouth is smoothed after welding. Because there, a step is not generated, thereby avoiding concentration of stress at the time of rotor rotation.

  Since the outer peripheral portion is a press-molded product and the mouth portion of the first fitting portion is formed as a press-thickening portion, the mouth portion can be easily smoothed.

  Further, since the outer peripheral portion is a press-formed product and the axial end portion of the outer peripheral surface is formed as a press-thickened portion, it is easy to attach the rotor core to the outer peripheral surface. Further, the axial length of the outer peripheral surface can be minimized. As a result, the axial length of the motor / generator in which the rotor is incorporated can be shortened.

  According to this invention, the inner peripheral portion including the fitting surface fitted to the rotating shaft, the outer peripheral surface to which the rotor core is fixed, and the annular end portion in the axial direction of the outer peripheral surface are connected and integrated with the outer peripheral surface. The outer peripheral portion having a hollow disc portion formed on the outer peripheral portion is coupled and held by the coupling portions respectively formed on the inner peripheral side end portion of the outer peripheral portion and the outer peripheral side end portion of the inner peripheral portion. Since the member is formed, it becomes easy to manufacture a holding member in which two parts (inner peripheral portion and outer peripheral portion) having a simple shape are combined, and the cost can be reduced.

  Since the outer peripheral part is formed in a cylindrical shape with a hollow lid with a hollow disk part at the axial annular end of the cylindrical outer peripheral surface, it can be manufactured by press molding (drawing process), and the cost can be reduced. Can be reduced. Moreover, since the disk part exists in the axial direction edge part, sufficient space can be ensured between a cylindrical outer peripheral surface and a rotating shaft.

  The cylindrical inner peripheral portion has a connecting portion on the inner peripheral portion side connected to a connecting portion of an inner peripheral side end portion of the disc portion (a hollow annular end portion of the hollow disc portion) on the inner peripheral portion side. Since it only needs to be formed at the outer peripheral side end, it is not necessary to provide a flange portion as in the prior art, and the inner peripheral portion includes a fitting surface that requires strength to be engaged with the rotating shaft and transmit torque The surface area of the portion that needs to be manufactured by forging can be reduced.

It is a partially omitted sectional view of a power unit including a motor of an electric vehicle in which a rotor according to this embodiment is incorporated. FIG. 2A is a perspective view of the holding member constituting the rotor as viewed from the side cover side (the outside in the axial direction of the motor), and FIG. 2B is a perspective view of the holding member as viewed from the inside in the axial direction of the motor. It is sectional drawing which shows the state which decomposed | disassembled the holding member before coupling | bonding into the outer peripheral part and the inner peripheral part. It is sectional drawing of the holding member integrated after the coupling | bonding of the inner peripheral part and the outer peripheral part. FIG. 5A is a partial cross-sectional explanatory view of a holding member according to this embodiment having an abutting surface and an abutting surface, and FIG. 5B is a partial cross-section of a holding member of a comparative example having neither an abutting surface nor an abutting surface. It is explanatory drawing. It is explanatory drawing of the press thickening part of the hollow inner peripheral part of a disc part. It is explanatory drawing of the press thickening part of the circumference part which is a connection part of an outer peripheral surface and a disk part. It is sectional drawing of the rotor hub which concerns on a prior art.

  Hereinafter, preferred embodiments of the rotor according to the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a partially omitted cross-sectional view of a power unit (at least a part including a motor 14 and a transmission) including a motor 14 of an electric vehicle 10 in which a rotor 12 according to this embodiment is incorporated.

  The motor 14 includes a stator 15 fixed to a cylindrical housing 100 with a bolt 104 via a stator holder 102 and the rotor 12.

  A side cover 106 that houses the motor 14 in the internal space of the housing 100 is attached to the housing 100 with bolts 108.

  The stator 15 includes a core 110 and a coil 112 wound around the core 110.

  The rotor 12 includes a rotating shaft 16 and a holding member 20 that is formed separately from the rotating shaft 16 and is fixed to the rotating shaft 16 and holds the rotor core 18 on the outer periphery. A plurality of permanent magnets 114 extending in the axial direction are embedded in the rotor core 18 in the circumferential direction.

  2A is a perspective view of the holding member 20 as viewed from the side cover 106 side (the outside in the axial direction of the motor 14), and FIG. 2B is a perspective view of the holding member 20 as viewed from the inside in the axial direction of the motor 14.

  The holding member 20 includes an inner peripheral portion 30 and an outer peripheral portion 32 (cylindrical outer surface, cylindrical outer peripheral surface). The inner peripheral portion 30 includes a fitting surface 22 that is configured in a cylindrical shape and is fitted to the rotating shaft 16 (see FIG. 1) by spline coupling. The outer peripheral portion 32 is formed in a cylindrical shape and is connected to the outer peripheral surface 24 to which the rotor core 18 is fixed and an annular end portion in the axial direction of the outer peripheral surface 24, and is formed in a disc shape (a bowl shape) integrally with the outer peripheral surface 24. Disk part 26 (saddle part, hollow disk part).

  A sufficient space 50 is secured between the outer peripheral surface 24 of the holding member 20 and the outer peripheral surface of the rotating shaft 16, and a part of the transmission 52 can be disposed in the space 50.

  FIG. 3 shows an exploded sectional view of the holding member 20 before joining, and FIG. 4 shows a sectional view of the holding member 20 after joining together.

  As described above, the holding member 20 includes the inner peripheral portion 30 including the fitting surface 22 and the outer peripheral portion 32 including the outer peripheral surface 24 (cylindrical outer peripheral surface) and the disk portion 26, and the coupling portion 34 (inner peripheral portion 30). After the inlay (indicator) is positioned and centered at the connecting portion 34i and the connecting portion 34e) of the outer peripheral portion 32, as shown in FIG. 4, it is joined by electron beam welding described later. As shown in FIG. 3, the coupling portion 34 (34 i, 34 e) is formed at the inner peripheral side end portion 26 a of the disk portion 26 and the outer peripheral side end portion 30 a of the inner peripheral portion 30.

  Further, the outer peripheral portion 32 is integrally provided with an axial protruding portion 38 that protrudes outward in the direction opposite to the outer peripheral surface 24 side with respect to the axial direction at the inner peripheral side end portion 26a of the disk portion 26. As shown in FIG. 1, a resolver rotor 42 that constitutes a rotation sensor 40 that detects the rotation angle of the rotor 12 is fixed to the outer peripheral surface of the protruding portion 38.

  The rotation sensor 40 is a resolver and includes a resolver rotor 42 fixed to the axial protrusion 38 and a resolver stator 44 (see FIG. 1) attached to the side cover 106.

  As shown in FIGS. 2A and 3, etc., a knock hole 46 for positioning the manufacturing process is provided in the disk portion 26, and a cooling oil passage hole 48 is provided in the inner peripheral portion 30.

  Basically, the holding member 20 according to the main part of the present invention that constitutes the rotor 12 constructed and operated as described above and manufactured (manufactured) will be described in more detail below. How to make).

  As shown in FIG. 1, the holding member 20 is integrated with the rotating shaft 16 by being fitted to the rotating shaft 16 through the fitting surface 22 of the inner peripheral portion 30 by spline coupling. The holding member 20 is a power unit that transmits the rotational power of the rotor 12 (rotor core 18) rotated by a rotating magnetic field generated by the stator 15 to a wheel (not shown) via the rotary shaft 16 and the transmission 52 constituting the rotor 12. The cylindrical inner peripheral part 30 for which a power transmission function and a cooling function are required.

  As described above, the inner peripheral portion 30 needs to satisfy the requirements of accuracy, tooth surface strength, hardness, accuracy / hardness as a centering spigot portion, and a convex shape. A so-called forging method, which is manufactured by performing carburizing and quenching on a spline formed on the surface 22 and performing post-cutting processing to remove a scale or the like, is applied.

  The holding member 20 has a cylindrical outer peripheral surface 24, a cylindrical axial protrusion 38, and an axial end of the cylindrical outer peripheral surface 24 connected to the outer peripheral side, while the cylindrical shaft It is composed of a hollow disk-shaped disk part 26 whose inner peripheral side is connected to the root part of the direction protruding part 38, and functional parts such as the rotor core 18 and the rotation sensor 40 are fixed, and these functional parts are easily fixed. The outer peripheral part 32 of the cylinder lid (substantially bowl) shape in which the cross section where the ease of an assembly is calculated | required becomes crank shape is provided.

  Here, the outer peripheral portion 32 is formed from a disc-shaped blank (workpiece) in a cross-sectional crank shape {a disc having a circular opening is regarded as a cylinder bottom, and is generally pivoted to an annular end portion of the outer periphery of the cylinder bottom. A shape in which a large cylindrical portion (outer peripheral surface 24) is formed in the direction, and a small cylindrical portion (axial protruding portion 38) is formed in an annular end portion of the circular opening at the bottom of the cylinder in a direction opposite to the axial direction} The press sheet metal manufacturing method, which is manufactured by press molding (drawing), that can be formed and minimizes processing, is applied.

  As shown in FIGS. 3 and 5A, the coupling portion 34 e of the inner peripheral side end portion 26 a of the disk portion 26 of the outer peripheral portion 32 has an abutting surface 62 formed so as to be orthogonal to the axial direction, and an axial direction. The first fitting portion 71 that forms the fitting portion is formed. On the other hand, the outer peripheral side end portion 30a of the inner peripheral portion 30 is abutted against the abutting surface 62. A contact surface 64 and a second fitting portion 72 that fits into the first fitting portion 71 are formed.

  Then, as shown in FIG. 5A, the abutment surface 64 of the second fitting portion 72 of the inner peripheral portion 30 is abutted against the abutting surface 62 of the first fitting portion 71 of the outer peripheral portion 32. In the state, the mouth portion 73 of the first fitting portion 71 and the second fitting portion 72 is smoothed (leveled), and in the smoothed state, the first fitting portion 71 and the second fitting portion The inner peripheral portion 30 and the outer peripheral portion 32 are joined by joining the mating portion 72 by forming a penetration shape as schematically shown by a large number of small dots by electron beam welding from the mouth portion 73 side. The holding member 20 (see FIG. 4) is manufactured (manufactured) by being firmly connected by the portion 34 (the connecting portion 34i of the inner peripheral portion 30 and the connecting portion 34e of the outer peripheral portion 32).

  As shown in FIG. 5B as a comparative example, when the abutting surface and the abutting surface are not formed on the outer peripheral portion 320 and the inner peripheral portion 300, respectively, spatter (melted metal) 330 from the penetration portion during welding. Is scattered and the mouth portion is not smoothed, a step portion is generated between the inner peripheral portion 300 and the outer peripheral portion 320, and there is a concern about concentration of stress.

  According to the holding member 20 according to this embodiment, as shown in FIG. 5A, spatter scattering is prevented by the close contact between the abutting surface 62 and the contact surface 64, and the mouth portion 73 is smoothed (the mouth smoothness). The stress can be dispersed throughout the first fitting portion 71 and the second fitting portion 72.

  As shown in FIG. 6, in the outer peripheral portion 32 that is a press-formed product, it is preferable that the mouth portion 73 of the first fitting portion 71 is formed as a press-thickening portion 80. Although it is difficult to secure the fitting length La in the press lead line 82, the press-increasing portion 80 can be used to increase the fitting length La and secure a reliable weld joint surface, and to weld. Stress concentration can be avoided by smoothing the mouth 73 and eliminating the step.

  As shown in FIG. 7, an annular end portion (circumferential portion) in the axial direction of the outer peripheral portion 32 that is a press-formed product is formed as a press-increasing portion 84, so that the fitting length Lb is achieved by the press lead line 86. Insufficient shortage can be avoided, and the axial length Lb of the outer peripheral surface 24 that fixes the rotor core 18 can be secured.

  As described above, the rotor 12 according to the above-described embodiment includes the rotating shaft 16 and the holding shaft that is formed separately from the rotating shaft 16 and is fixed to the rotating shaft 16 and holds the rotor core 18. 20.

  The holding member 20 includes a fitting surface 22 fitted to the rotary shaft 16, an inner peripheral portion 30 manufactured by forging, an outer peripheral surface 24 (cylindrical outer surface) to which the rotor core 18 is fixed, and an axial direction of the outer peripheral surface 24. An outer peripheral portion 32 that is press-molded with a hollow disc portion 26 that is connected to the annular end portion of the outer peripheral surface 24 and is formed integrally with the outer peripheral surface 24. The inner peripheral side of the disc portion 26 of the outer peripheral portion 32. Inlay positioning is performed by the coupling portions 34 (the coupling portion 34i of the inner circumferential portion 30 and the coupling portion 34e of the outer circumferential portion 32) respectively formed on the end portion 26a (FIG. 3) and the outer circumferential side end portion 30a of the inner circumferential portion 30. It is manufactured by joining by electron beam welding.

  Since it is configured to form (manufacture) two parts (inner peripheral part 30 and outer peripheral part 32) having a simple shape without the flange part 208 (see FIG. 8) as in the prior art, the holding Manufacture of the member 20 is facilitated, the material cost of the inner periphery 30 is reduced, and the number of finishing processes such as scale removal (cutting to a desired shape, removal of oxide film on the surface, removal of burn, etc.) is reduced. It can reduce and cost can be reduced. In addition, since the disk portion 26 is integrally formed (cross-sectional crank shape) on the annular end portion in the axial direction of the outer peripheral surface 24 (cylindrical outer surface), the outer peripheral portion 32 can be press-formed with an upper die and a lower die. An easy shape can be obtained, and a sufficient space 50 can be secured between the rotating shaft 16 and the outer peripheral surface 24.

  Note that the present invention is not limited to the above-described embodiment, and it is needless to say that various configurations can be adopted based on the contents described in this specification.

DESCRIPTION OF SYMBOLS 10 ... Electric vehicle 12 ... Rotor 14 ... Motor 15 ... Stator 16 ... Rotating shaft 18 ... Rotor core 20 ... Holding member 22 ... Fitting surface 24 ... Outer peripheral surface 26 ... Disk part (hollow disk part)
30 ... Inner peripheral part 32 ... Outer peripheral part 34, 34e, 34i ... Joint part

Claims (5)

A rotation axis;
A rotor that is formed separately from the rotating shaft, is fixed to the rotating shaft, and has a holding member that holds a rotor core on the outer periphery.
The holding member is
A fitting surface configured in a cylindrical shape and fitted to the rotating shaft;
An outer peripheral surface configured in a cylindrical shape to which the rotor core is fixed;
A hollow disk-shaped disk part connected to the annular annular end of the outer peripheral surface and formed integrally with the outer peripheral surface;
The holding member is
An inner peripheral part including the fitting surface and an outer peripheral part including the outer peripheral surface and the disc part are combined at a connecting part, and configured.
The said coupling | bond part is formed in the inner peripheral side edge part of the said disk part, and the outer peripheral side edge part of the said inner peripheral part. The rotor characterized by the above-mentioned. The rotor according to claim 1, wherein
The outer periphery is
In the end portion on the inner peripheral side of the disk portion, provided with an axial projecting portion projecting outward in the opposite direction to the outer peripheral surface side with respect to the axial direction,
A rotation sensor for detecting a rotation angle of the rotor is fixed to the axial protrusion. The rotor according to claim 1 or 2,
The inner peripheral side end of the disk part is formed with an abutment surface provided in a direction orthogonal to the axial direction and a first fitting part that forms a fitting part in the axial direction,
At the outer peripheral side end portion of the inner peripheral portion, a contact surface that is abutted against the abutting surface and a second fitting portion that fits into the first fitting portion are formed,
In the state where the abutting surface of the second fitting portion is abutted against the abutting surface of the first fitting portion, the mouth portions of the first fitting portion and the second fitting portion are smooth. The rotor, wherein the first fitting portion and the second fitting portion are joined by welding from the mouth portion side in a state of being smoothed and smoothed. The rotor according to claim 3, wherein
The outer peripheral portion is a press-formed product,
The rotor, wherein the mouth portion of the first fitting portion is formed as a press-thickening portion. The rotor according to claim 3 or 4,
The outer peripheral portion is a press-formed product,
An axial end portion of the outer peripheral surface is formed as a press thickening portion.

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