Rotating electric machine and rotor manufacturing method

Abstract

This provides a sleeve with improved strength while avoiding increased weight. [Solution] The rotor of the rotating electric machine has a sleeve that covers the outer surface of the permanent magnet. The sleeve has a hoop layer 62. The hoop layer 62 includes a leading ring portion 66A that is formed relatively in advance when the fiber bundle of fiber-reinforced resin is wound around it, and a trailing ring portion 66B that is formed following the leading ring portion 66A and adjacent to the leading ring portion 66A. The trailing ring portion 66B has an overlapping portion 68 that overlaps the leading ring portion 66A. The direction perpendicular to the longitudinal direction of the fiber bundle is defined as the width direction, and the ratio of the width direction dimension (second width dimension OV) of the overlapping portion 68 to the width direction dimension (first width dimension W) of the fiber bundle is defined as the overlap ratio. The overlap ratio is 20% to 85%.

Description

Technical Field

[0001] The present invention relates to a rotating electric machine including a rotor and a stator. The present invention also relates to a method for manufacturing a rotor that constitutes the rotating electric machine.

Background Art

[0002] In a rotor of a surface magnet (SPM) type rotating electric machine, permanent magnets are arranged on the outer periphery of a rotating shaft. When the rotating shaft rotates during operation of the rotating electric machine, a force in a direction to separate from the rotating shaft is applied to the permanent magnets due to centrifugal force. In order to prevent the permanent magnets from detaching from the rotating shaft, a sleeve is arranged on the outer periphery of the permanent magnets. The sleeve holds the permanent magnets on the rotating shaft.

[0003] The sleeve is manufactured, for example, by winding a fiber bundle of carbon fiber reinforced resin around a mandrel. Japanese Patent Application Laid-Open No. 2017-163752 discloses a sleeve having an inner layer formed by hoop winding of a fiber bundle and an outer layer formed by helical winding of a fiber bundle.

[0004] Also, the applicant has proposed a sleeve in which three carbon fiber reinforced resin layers having different elastic moduli are laminated in Japanese Patent Application Laid-Open No. 2023-48245.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] When the sleeve is attached to the rotating shaft, the sleeve expands in diameter. In this expanded state, the rotating shaft passes through the sleeve, and the sleeve tightens around the permanent magnet due to its elastic restoring force. The sleeve must be resistant to damage during expansion.

[0007] The present invention aims to solve the problems described above. [Means for solving the problem]

[0008] A first aspect of the present disclosure is a rotating electric machine comprising a rotor and a stator, wherein the rotor has a rotating shaft and a permanent magnet held on the rotating shaft, and the stator has an electromagnetic coil surrounding the permanent magnet, wherein the rotor has a sleeve covering the outer surface of the permanent magnet, the sleeve has a hoop layer formed by hoop winding of fiber bundles of fiber-reinforced resin, the hoop layer includes a plurality of annular portions formed by the annular curvature of the fiber bundles, and the plurality of annular portions are formed by the continuous winding of the fiber bundles A rotating electric machine having a leading ring portion that is formed relatively earlier when the fiber bundle is formed, and a trailing ring portion that is formed following the leading ring portion and adjacent to the leading ring portion in the axial direction of the rotor, wherein when the direction perpendicular to the longitudinal direction of the fiber bundle is defined as the width direction, the trailing ring portion has an overlapping portion formed by at least one end of the trailing ring portion in the width direction overlapping the leading ring portion in the radial direction of the rotor, and the overlap ratio, which is the ratio of the width direction dimension of the overlapping portion to the width direction dimension of the fiber bundle, is 20% to 85%.

[0009] A second aspect of the present disclosure is a method for manufacturing a rotor surrounded by a stator in a rotating electric machine, having a rotating shaft and a permanent magnet held on the rotating shaft, the method comprising a hoop layer forming step of winding a bundle of fiber-reinforced resin fibers in a hoop winding manner on the outer surface of the permanent magnet to form a hoop layer including a plurality of annular portions in which the fiber bundle is curved in an annular shape, wherein in the plurality of annular portions, the annular portion formed relatively earlier when the fiber bundle is wound continuously is called the leading ring portion, the annular portion formed following the leading ring portion and adjacent to the leading ring portion in the axial direction of the rotor is called the succeeding ring portion, and the direction perpendicular to the longitudinal direction of the fiber bundle is called the width direction, the method for manufacturing a rotor comprising, in the hoop layer forming step, overlapping a portion by overlapping at least one end of the succeeding ring portion in the width direction with one end of the leading ring portion in the width direction in the radial direction of the rotor, and the overlap ratio, which is the ratio of the width direction dimension of the overlapping portion to the width direction dimension of the fiber bundle, is 20% to 85%. [Effects of the Invention]

[0010] According to this disclosure, it is possible to construct a sleeve with improved strength while avoiding an increase in weight. [Brief explanation of the drawing]

[0011] [Figure 1] Figure 1 is a schematic cross-sectional view of the main parts of the rotating electric machine according to this embodiment, viewed from a direction perpendicular to the axial direction. [Figure 2] Figure 2 is a schematic side view of the rotor, which constitutes a rotating electric machine, as seen from a direction perpendicular to the axial direction. [Figure 3] Figure 3 is a schematic perspective view of the ring member that makes up the sleeve. [Figure 4] Figure 4 is a schematic cross-sectional view of the main part of the sleeve as seen from a direction perpendicular to the axial direction. [Figure 5] Figure 5 is a schematic cross-sectional view of the main part of the hoop layer (laminated hoop layer) that constitutes the sleeve, viewed from a direction perpendicular to the axial direction. [Figure 6]FIG. 6 is a graph showing the change in the maximum diameter expansion rate (expansion limit) with respect to the change in the overlapping ratio. [Figure 7] FIG. 7 is a schematic flow chart of the manufacturing method of the rotor according to the present embodiment. [Figure 8] FIG. 8 is an explanatory diagram showing a state where a hoop layer is formed in the hoop layer forming step. [Figure 9] FIG. 9 is a schematic perspective view of a semi-finished product that becomes a sleeve. [Figure 10] FIG. 10 is a graph showing the strength distribution in an annular test piece cut out from a predetermined location of the semi-finished product. [Figure 11] FIG. 11 is an explanatory diagram showing a state where a ring member obtained from a semi-finished product is attached to a rotating shaft.

MODE FOR CARRYING OUT THE INVENTION

[0012] In FIGS. 1 to 11, some components may be exaggerated for emphasis. That is, in FIGS. 1 to 11, each component is not necessarily shown at the correct scale.

[0013] FIG. 1 is a schematic cross-sectional view of a main part of the rotating electrical machine 10 according to the present embodiment as viewed from a direction orthogonal to the axial direction. The rotating electrical machine 10 includes a rotor 12 and a stator 14. Most of the rotor 12 and the stator 14 are housed in a casing 16.

[0014] The rotor 12 has a rotating shaft 18. The rotating shaft 18 is a cylindrical body having a first small-diameter portion 20, a large-diameter portion 22, and a second small-diameter portion 24. The first small-diameter portion 20 is connected to one end of the large-diameter portion 22 in the axial direction, and the second small-diameter portion 24 is connected to the other end of the large-diameter portion 22 in the axial direction. The axis M is a line that passes through the centers of the first small-diameter portion 20, the large-diameter portion 22, and the second small-diameter portion 24 and extends along the extending direction of the rotating shaft 18.

[0015] The axial direction is the direction parallel to the axis M and is the direction of the arrow X in FIG. 1. The diameters of the first small-diameter portion 20, the large-diameter portion 22, and the second small-diameter portion 24 each extend in a direction orthogonal to the axis M. Hereinafter, the direction in which the diameter extends may be referred to as the radial direction. The radial direction is the direction of the arrow Y in FIG. 1.

[0016] The rotating shaft 18 is rotatably supported by the casing 16 via the first bearing 26 and the second bearing 28. The tips of the first small-diameter portion 20 and the second small-diameter portion 24 of the rotating shaft 18 are respectively passed through the first bearing 26 and the second bearing 28 and exposed from the casing 16. For example, a propeller (not shown) or the like is attached to the tip exposed from the casing 16.

[0017] A permanent magnet 30 is disposed on the outer peripheral portion of the large-diameter portion 22. The rotating shaft 18 is further provided with a sleeve 40. In a state before the large-diameter portion 22 is passed through the sleeve 40 (natural state), the inner diameter of the sleeve 40 is smaller than the diameter of the large-diameter portion 22. Therefore, the sleeve 40 is disposed on the outer periphery of the large-diameter portion 22 in a state of being expanded with elastic deformation.

[0018] The sleeve 40 clamps the permanent magnet 30 inward in the radial direction by an elastic restoring force at a position covering the outer surface of the permanent magnet 30. Thereby, the permanent magnet 30 is held by the large-diameter portion 22 which is a part of the rotating shaft 18.

[0019] The stator 14 has an electromagnetic coil 34. The electromagnetic coil 34 is provided on a stator core (not shown). When the stator 14 is positioned and fixed to the casing 16 and the large-diameter portion 22 of the rotating shaft 18 and the permanent magnet 30 are accommodated in the casing 16, the electromagnetic coil 34 surrounds the permanent magnet 30 through the sleeve 40. When the permanent magnet 30 and the rotating shaft 18 rotate integrally, an alternating magnetic field is formed between the permanent magnet 30 and the electromagnetic coil 34.

[0020] The sleeve 40 will now be described. As shown in Figures 1 and 2, the sleeve 40 has a plurality of annular ring members 42. The plurality of ring members 42 are arranged along the axial direction on the outer surface of the large diameter portion 22. As a result, the sleeve 40 is cylindrical as a whole. As will be described later, the plurality of ring members 42 are obtained by cutting them from a single semi-finished product 44 (see Figure 9).

[0021] Figure 3 is a schematic perspective view of a single ring member 42. Figure 3 shows an embodiment in which each ring member 42 has an inner layer 50 and an outer layer 60. The inner layer 50 is the inner layer in the radial direction of the sleeve 40, and the outer layer 60 is the outer layer in the radial direction of the sleeve 40. That is, the outer layer 60 is laminated on the inner layer 50.

[0022] The inner layer 50 and the outer layer 60 differ in the way the fiber bundle 70 shown in Figure 8 is wound. In the embodiment shown in Figure 4, the inner layer 50 includes a helical layer 52, and the outer layer 60 includes a hoop layer 62. However, the helical layer 52 is not essential for each ring member 42. Also, when each ring member 42 has a helical layer 52, the inner layer 50 may include a hoop layer 62 and the outer layer 60 may also include a helical layer 52, the opposite of Figure 4.

[0023] The embodiment shown in Figure 4 will be described below. As described above, the inner layer 50 includes a helical layer 52. As shown in Figure 8, the helical layer 52 is a layer formed by helically winding a fiber bundle 70 of fiber-reinforced resin (for example, carbon fiber reinforced resin). In helical winding, the fiber bundle 70 intersects with respect to the axial direction at an intersection angle α. The intersection angle α is not particularly limited, but is preferably 30° to 60°. In this case, the difference between the intersection angle α and the intersection angle β in the hoop layer 62 that constitutes the outer layer 60 is not very large. For this reason, it is easy to form the hoop layer 62, which is the innermost layer of the outer layer 60, following the helical layer 52, which is the outermost layer of the inner layer 50.

[0024] By constructing the inner layer 50 with a helical layer 52, when the ring member 42 is attached to the rotating shaft 18, the fiber bundle 70 that contacts the outer surface of the rotating shaft 18 (the fiber bundle 70 constituting the innermost layer of the ring member 42) is prevented from shifting relative to other fiber bundles 70. In the following description, the fiber bundle 70 constituting the innermost layer of the ring member 42 will be referred to as the "innermost fiber bundle".

[0025] The inner layer 50 may be composed of a single helical layer 52, but as shown in Figure 4, it is preferable to compose the inner layer 50 with multiple helical layers 52. In this case, displacement of the innermost fiber bundle is further suppressed. Hereinafter, the layer formed by stacking multiple helical layers 52 will be referred to as the laminated helical layer 54.

[0026] In the laminated helical layer 54, the preferred total number N1 of helical layers 52 is, for example, about 2 to 8 layers. When the helical layers 52 constituting the laminated helical layer 54 are named as the 1st layer 52a, 2nd layer 52b, 3rd layer (not shown), 4th layer (not shown), etc., from the inside out, the inclination direction of the fiber bundles 70 with respect to the axial direction is opposite to that of the odd-numbered layers (for example, the 1st layer 52a and the 3rd layer not shown) and the even-numbered layers (for example, the 2nd layer 52b and the 4th layer not shown).

[0027] The outer layer 60 is composed of a hoop layer 62. As shown in Figure 8, the hoop layer 62 is a layer formed by hoop winding a fiber bundle 70 of fiber-reinforced resin. In hoop winding, the fiber bundle 70 intersects with respect to the axial direction at a predetermined intersection angle β. Depending on the first width W of the fiber bundle 70 (see Figure 5), the intersection angle β is, for example, in the range of approximately 89° or more and less than 90°. The hoop layer 62 that constitutes the outer layer 60 provides a clamping force that tightens the permanent magnet 30 radially inward. In addition, the overlapping portion 68 shown in Figure 5 increases the strength of each ring member 42 (sleeve 40).

[0028] The outer layer 60 may be composed of a single hoop layer 62, but it is preferable to compose the outer layer 60 with multiple hoop layers 62, as shown in Figure 4. In this case, the strength of each ring member 42 (sleeve 40) is further increased. Hereinafter, the layer formed by stacking multiple hoop layers 62 will be referred to as the stacked hoop layer 64.

[0029] In the laminated hoop layer 64, the preferred total number of hoop layers 62 N2 is, for example, about 12 to 16 layers. Therefore, the preferred total number of hoop layers 62 N2 in the laminated hoop layer 64 is 2 to 8 times the total number of helical layers 52 N1 in the laminated helical layer 54. In this case, the strength of each ring member 42 can be increased while more effectively avoiding misalignment of the innermost fiber bundles of each ring member 42.

[0030] Let the thickness of the inner layer 50 be the first layer thickness T1, and the thickness of the outer layer 60 be the second layer thickness T2. The ratio of the second layer thickness T2 to the first layer thickness T1 is substantially the same as the ratio of the total number of layers N2 of the hoop layer 62 to the total number of layers N1 of the helical layer 52. That is, the second layer thickness T2 is preferably 2 to 8 times the first layer thickness T1.

[0031] As shown in Figure 5, the hoop layer 62 has an overlapping portion 68. This overlapping portion 68 will now be explained. In Figure 5, the innermost first layer 62a, the second layer 62b which is laminated on the first layer 62a, and the third layer 62c which is laminated on the second layer 62b are typically shown in the laminated hoop layer 64.

[0032] The hoop layer 62 includes a plurality of annular sections 66 in which the fiber bundle 70 is curved in an annular shape. Each annular section 66 is formed when the fiber bundle 70 is wound onto the mandrel 80 by hoop winding, as shown in Figure 8. Each annular section 66 is a unit ring formed by the fiber bundle 70 making one full turn around an axis M. During the forward movement, when the fiber bundle 70 is wound from the first end 82, which is one end in the longitudinal direction of the mandrel 80, to the second end (not shown), which is the other end in the longitudinal direction, the plurality of annular sections 66 are formed sequentially from the first end 82 to the second end. In contrast, during the return movement, when the fiber bundle 70 is wound from the second end to the first end 82, the plurality of annular sections 66 are formed sequentially from the second end to the first end 82 (see Figure 5).

[0033] Hereinafter, in adjacent annular sections 66 in the axial direction, the annular section 66 that is formed relatively earlier when the fiber bundle 70 is continuously wound will be called the leading annular section 66A, and the annular section 66 that is formed immediately following the leading annular section 66A will be called the following annular section 66B. In odd-numbered layers formed during forward movement (for example, the first layer 62a and the third layer 62c in Figure 5), among two adjacent annular sections 66, the annular section 66 closer to the first end 82 is the leading annular section 66A, and the annular section 66 closer to the second end is the following annular section 66B. In even-numbered layers formed during return movement (for example, the second layer 62b in Figure 5), among two adjacent annular sections 66, the annular section 66 closer to the second end is the leading annular section 66A, and the annular section 66 closer to the first end 82 is the following annular section 66B.

[0034] The direction perpendicular to the longitudinal direction of the fiber bundle 70 is called the width direction. The width direction of the fiber bundle 70 in the hoop layer 62 is substantially the same as the axial direction of the rotor 12. In Figure 5, the width direction is parallel to the axial direction. As can be seen from Figure 5, the overlapping portion 68 is formed when at least one end of the trailing ring portion 66B in the width direction overlaps the leading ring portion 66A in the radial direction of the rotor 12. That is, the annular portion 66 having the overlapping portion 68 is the trailing ring portion 66B.

[0035] The width dimension of the fiber bundle 70 is defined as the first width dimension W, and the width dimension of the overlapping portion 68 is defined as the second width dimension OV. The ratio of the second width dimension OV to the first width dimension W is defined as the overlap ratio. That is, the overlap ratio can be calculated using the following formula. Overlap ratio [%] = (OV / W) × 100

[0036] In this embodiment, the overlap ratio is 20% to 85%. When the overlap ratio is 20% or more, the overlapping portion 68 does not peel off from the leading ring portion 66A. That is, the overlapping portion 68 firmly covers a part of the leading ring portion 66A. Each ring member 42 having such an overlapping portion 68 exhibits great strength. Furthermore, when the overlap ratio is 85% or less, the number of times the fiber bundle 70 is wound when forming the hoop layer 62 is avoided to be excessively large, and the thickness of the hoop layer 62 is avoided to be excessively large. Therefore, it is possible to suppress an increase in the weight of the sleeve 40.

[0037] In this way, by setting the overlap ratio to 20% to 85%, it is possible to construct a sleeve 40 that is heavy and has improved strength. A more preferable range for the overlap ratio is 30% to 50%.

[0038] Each ring member 42 (sleeve 40) configured as described above has a large expansion limit. Specifically, let D0 be the diameter of each ring member 42 (see Figure 3) before it is mounted on the rotating shaft 18, and D1 be the maximum diameter that each ring member 42 can expand to. The maximum expansion ratio of each ring member 42 is calculated using the following formula. Here, the maximum expansion ratio is the expansion limit just before each ring member 42 begins to break beyond the elastic deformation range. The inner diameter is used as the diameter. Maximum diameter expansion ratio (expansion limit) = {(D1-D0) / D0} × 100

[0039] Figure 6 is a graph showing the change in the expansion limit when the overlap ratio is changed. The expansion test was conducted at room temperature (22°C) or under atmospheric pressure at 150°C. From Figure 6, it can be seen that when the overlap ratio is in the range of 20% to 85%, the expansion limit of each ring member 42 is 1.2% or more at both room temperature and 150°C.

[0040] As shown in Figure 11, each ring member 42 expands slightly in diameter by elastic deformation from its natural state where its inner diameter (diameter) is D0, and is mounted on the large-diameter portion 22 of the rotating shaft 18. In this embodiment, since the expansion limit of each ring member 42 is 1.2% or more, damage to each ring member 42 is avoided when mounting each ring member 42 on the large-diameter portion 22.

[0041] The diameter of each ring member 42 mounted on the large-diameter section 22 is slightly larger than the diameter D0 in its natural state. As a result, each ring member 42 tightens the permanent magnet 30 radially inward due to its elastic restoring force. This prevents the permanent magnet 30 from falling off the rotating shaft 18 due to centrifugal force when the rotor 12 rotates.

[0042] The rotating electric machine 10, configured as described above, can be mounted on an aircraft and used as a motor. When the motor is driven, the electromagnetic coil 34 shown in Figure 1 is energized. This energization creates a magnetic field around the electromagnetic coil 34. A repulsive or attractive force acts between this magnetic field and the permanent magnet 30, causing the rotating shaft 18 to begin rotating around its axis M.

[0043] In aircraft, high output is sometimes required from the motor. In this embodiment, since the weight of the sleeve 40 is kept from increasing, it is possible to rotate the rotating shaft 18 at high speed even when the rotational torque applied from the electromagnetic coil 34 to the rotating shaft 18 is small. In other words, the rotating electric machine 10 can respond to situations where high output is required.

[0044] The rotating electric machine 10 can also be used as a generator. In this case, the driving force that rotates the rotating shaft 18 is converted into electrical energy output from the electromagnetic coil 34. As described above, the rotating shaft 18 can be rotated at high speed with a small driving force, so high-output electrical energy can be obtained.

[0045] Next, the manufacturing method for the rotor 12 that constitutes the rotating electric machine 10 will be described. Here, the method of carrying out the helical layer formation step S1 and the hoop layer formation step S2 will be described, as shown in the schematic flow in Figure 7. However, when manufacturing a sleeve 40 that does not have a helical layer 52, it is not necessary to carry out the helical layer formation step S1.

[0046] In the helical layer formation step S1 and the hoop layer formation step S2, fiber bundles 70 of fiber-reinforced resin are wound around the mandrel 80 shown in Figure 8. The winding can be performed by known methods such as the filament winding method. A suitable example of the reinforcing fiber in the fiber-reinforced resin is carbon fiber. The reinforcing fiber may also be glass fiber or metal fiber. Suitable examples of the matrix resin in the fiber-reinforced resin are epoxy resin, cyanate ester resin, or vinyl ester resin.

[0047] The mandrel 80 has a first end 82, which is one end in the longitudinal direction, and a second end (not shown), which is the other end in the longitudinal direction. Hereinafter, the movement of the fiber bundle 70 when winding starts at the first end 82 and ends at the second end is called the forward movement. In the forward movement, odd-numbered helical layers 52 or odd-numbered hoop layers 62 are formed. Conversely, the movement of the fiber bundle 70 when winding starts at the second end and ends at the first end 82 is called the return movement. In the return movement, even-numbered helical layers 52 or even-numbered hoop layers 62 are formed.

[0048] In the helical layer formation process S1, first, the fiber bundle 70 is moved forward. During forward movement, the fiber bundle 70 is wound around the mandrel 80 such that it rises from the first end 82 towards the second end. The intersection angle α of the fiber bundle 70 with respect to the axial direction is preferably 30° to 60°.

[0049] Next, the fiber bundle 70 is moved back. During the return movement, the fiber bundle 70 is wrapped around the mandrel 80 so that it rises as it moves from the second end to the first end 82. The intersection angle α of the fiber bundle 70 with respect to the axial direction during the return movement is the same as the intersection angle during the forward movement, but in the opposite direction.

[0050] When forming three or more helical layers 52, the fiber bundle 70 is moved forward and backward a predetermined number of times. Based on one round trip of the fiber bundle 70, two helical layers 52 are formed.

[0051] After obtaining the laminated helical layer 54 (inner layer 50) as described above, the hoop layer formation process S2 is carried out. Specifically, the fiber bundles 70 are wound around the mandrel 80 via the inner layer 50 such that the intersection angle β of the fiber bundles 70 with respect to the axis M is, for example, 89° to less than 90°. At this time, a plurality of annular portions 66 are formed on the inner layer 50.

[0052] During forward and return movement, two annular sections 66 adjacent to each other in the axial direction are in the relationship of a leading annular section 66A and a trailing annular section 66B. That is, the annular section 66 formed relatively earlier is the leading annular section 66A, and the annular section 66 formed following the leading annular section 66A is the trailing annular section 66B. The trailing annular section 66B has an overlapping portion 68 as shown in Figure 5. As described above, the overlapping ratio is 20% to 85%. A more preferable overlapping ratio is 30% to 50%. In a semi-finished product 44 with an axial length L of 200 mm, the number of overlapping portions 68 (see Figure 5) included in each hoop layer 62 is, for example, 65 to 250.

[0053] When forming three or more hoop layers 62, the fiber bundle 70 is moved forward and backward a predetermined number of times. Based on one round trip of the fiber bundle 70, two hoop layers 62 are formed. This gives a laminated hoop layer 64 (outer layer 60). As described above, the total number of hoop layers 62 constituting the laminated hoop layer 64, N2, is preferably 2 to 8 times the total number of helical layers 52 constituting the laminated helical layer 54, N1.

[0054] Next, the matrix resin in the fiber-reinforced resin is cured. That is, heat is applied to the inner layer 50 and the outer layer 60. As a result, a semi-finished product 44 is obtained as shown in Figure 9. The semi-finished product 44 is in the shape of a single long collar. In the cutting process S3 shown in Figure 7, the semi-finished product 44 is cut into, for example, 10 ring members 42 (see Figure 3). However, the number of ring members 42 cut from one semi-finished product 44 is not limited to 10. Alternatively, the semi-finished product 44 may be used as a sleeve 40 without being cut.

[0055] Figure 10 is a graph showing the distribution of fracture strength (tensile strength) in five annular test pieces cut from predetermined locations on multiple semi-finished products 44 of the same shape and dimensions. In all of the multiple semi-finished products 44, the axial length L (see Figure 9) is 200 mm. The five annular test pieces were cut from the following locations: 20 mm from one end of the semi-finished product 44 in the longitudinal direction, between 40 mm and 60 mm from that end, between 90 mm and 110 mm from that end, between 140 mm and 160 mm from that end, and from 180 mm from one end of the semi-finished product 44 to the other end in the longitudinal direction.

[0056] Figure 10 shows that the strength of all the annular test specimens is within the ±3σ range. From this, it can be determined that when the sleeve 40 is divided into multiple ring members 42, each ring member 42 has approximately the same strength as the others.

[0057] Next, the mounting process S4 shown in Figure 7 is performed. In the mounting process S4, each ring member 42 is mounted on the large diameter portion 22 using the mounting jig 90 shown in Figure 11.

[0058] A brief description of the mounting jig 90 is provided below. The mounting jig 90 has a small-diameter end 92 which is one end in the axial direction, a large-diameter end 93 which is the other end in the axial direction, and a tapered portion 94 which tapers in diameter from the large-diameter end 93 toward the small-diameter end 92. The outer diameter of the small-diameter end 92 is less than or equal to the diameter (inner diameter) D0 of the sleeve 40 (each ring member 42) in its natural state. The outer surface of the large-diameter end 93 substantially coincides with the outer surface of the permanent magnet 30 held in the large-diameter portion 22. The mounting jig 90 further has an insertion hole 96 that extends axially from the small-diameter end 92 toward the large-diameter end 93.

[0059] The first small-diameter portion 20 of the rotating shaft 18 is inserted into the insertion hole 96. This insertion attaches the mounting jig 90 to the rotating shaft 18. The large-diameter end 93 of the mounting jig 90 is adjacent to the large-diameter portion 22 of the rotating shaft 18. The small-diameter end 92 of the mounting jig 90 is oriented in a direction away from the large-diameter portion 22 of the rotating shaft 18 in the axial direction.

[0060] In the mounting process S4, as shown in Figure 11, the mounting jig 90 is passed through the ring member 42. That is, the small diameter end 92 is first inserted into the inside of the ring member 42. Since the outer diameter of the small diameter end 92 is less than or equal to the diameter D0 of the sleeve 40 (each ring member 42) in its natural state, the small diameter end 92 is lightly press-fitted into the ring member 42.

[0061] Next, the ring member 42 is moved relative to the large-diameter end 93 by a pressing mechanism (not shown) or the like. During this relative movement, the inner circumferential surface of the inner layer 50 of the ring member 42 slides relative to the outer circumferential surface of the tapered portion 94. As a result, the inner diameter of the ring member 42 is gradually expanded to match the outer diameter of the tapered portion 94. When the ring member 42 reaches the large-diameter end 93, the position of the inner surface of the ring member 42 substantially coincides with the position of the outer surface of the permanent magnet 30 attached to the large-diameter portion 22. Therefore, the large-diameter portion 22 and the permanent magnet 30 can be easily inserted into the ring member 42.

[0062] In the embodiment shown in Figure 4, the inner circumferential surface of the ring member 42 is a helical layer 52. In this embodiment, when the ring member 42 is attached to the rotating shaft 18, the helical layer 52 slides against the outer surface of the permanent magnet 30. At this time, the helical layer 52 suppresses misalignment of the innermost fiber bundle relative to the other fiber bundles 70.

[0063] By arranging multiple ring members 42 along the axial direction of the large-diameter portion 22, the outer surface of the permanent magnet 30 is covered by the sleeve 40. The sleeve 40 (multiple ring members 42) tightens the permanent magnet 30 radially inward due to its elastic restoring force. As a result, a rotor 12 (see Figure 2) is obtained in which the permanent magnet 30 is held by the sleeve 40 on the outer circumference of the rotating shaft 18.

[0064] This embodiment provides the following effects.

[0065] The rotor 12 constituting the rotating electric machine 10 has a sleeve 40 that covers the outer surface of a permanent magnet 30 held on a rotating shaft 18. The sleeve 40 has a hoop layer 62, which includes a leading ring portion 66A and a trailing ring portion 66B. The trailing ring portion 66B has an overlapping portion 68 that overlaps the leading ring portion 66A. When the ratio of the widthwise dimension (second width dimension OV) of the overlapping portion 68 to the widthwise dimension (first width dimension W) of the fiber bundle 70 is defined as the overlapping ratio, the overlapping ratio is set to 20% to 85%.

[0066] In the hoop layer 62, a portion of the trailing ring portion 66B overlaps with the leading ring portion 66A, thus creating a sleeve 40 with improved strength. Therefore, the sleeve 40 is less likely to break when mounted on the rotating shaft 18. Furthermore, by setting the overlap ratio within the range of 20% to 85%, the strength of the sleeve 40 can be increased while suppressing an increase in the weight of the hoop layer 62. A more preferable overlap ratio is 30% to 50%.

[0067] In the embodiment shown in Figure 4, the sleeve 40 has a helical layer 52. The helical layer 52 constitutes an inner layer 50 that covers the outer surface of the permanent magnet 30. As a result, when the sleeve 40 is attached to the rotating shaft 18, the inner layer 50 formed by the helical layer 52 slides against the outer surface of the permanent magnet 30. At this time, the helical layer 52 suppresses misalignment of the innermost fiber bundle relative to the fiber bundle 70 in the axial direction of the rotating shaft 18.

[0068] In the helical layer 52, the intersection angle α (see Figure 8) between the fiber bundle 70 and the axial direction of the rotating shaft 18 is, for example, 30° to 60°. In this case, the angle difference (β-α) between the helical layer 52 and the hoop layer 62 is not very large, so it is easy to form the hoop layer 62 following the helical layer 52.

[0069] In the embodiment shown in Figure 4, the inner layer 50 is a laminated helical layer 54 in which multiple helical layers 52 are stacked, and the outer layer 60 is a laminated hoop layer 64 in which multiple hoop layers 62 are stacked. The total number of hoop layers 62 in the laminated hoop layer 64, N2, is, for example, 2 to 8 times the total number of helical layers 52 in the laminated helical layer 54, N1.

[0070] In this configuration, displacement of the innermost fiber bundle in the helical layer 52 is further suppressed. Furthermore, the strength of the sleeve 40 can be effectively improved.

[0071] When the diameter of the sleeve 40 before it is attached to the rotating shaft 18 (in its natural state) is D0, and the maximum diameter that the sleeve 40 can expand to is D1, the maximum expansion ratio calculated by the following formula is 1.2% or more. Maximum diameter expansion rate = {(D1-D0) / D0}×100

[0072] Because the maximum expansion ratio of the sleeve 40 is large, damage to the sleeve 40 when attaching it to the rotating shaft 18 is more effectively avoided.

[0073] As shown in Figure 7, the manufacturing method of the rotor 12 includes a hoop layer formation step S2. In the hoop layer formation step S2, the trailing ring portion 66B is superimposed on the leading ring portion 66A such that the superimposition ratio is 20% to 85% (see Figure 8). This makes it possible to obtain a sleeve 40 that avoids increasing weight and improves strength. When the superimposition ratio is 30% to 50%, the maximum diameter expansion ratio (expansion limit) of the sleeve 40 can be effectively increased (see Figure 6).

[0074] When manufacturing the sleeve 40 in the configuration shown in Figure 4, the manufacturing method for the rotor 12 includes a helical layer formation step S1 in which a helical layer 52 is formed by winding a fiber bundle 70 in a helical winding manner (see Figure 7). The helical layer formation step S1 is performed before the hoop layer formation step S2. Therefore, the helical layer 52 is formed as an inner layer 50 that covers the outer surface of the permanent magnet 30, and the hoop layer 62 is formed as an outer layer 60 that is laminated on the helical layer 52.

[0075] By making the helical layer 52 the inner layer 50, when the sleeve 40 is attached to the rotating shaft 18, displacement of the innermost fiber bundle constituting the helical layer 52 is suppressed.

[0076] In the helical layer formation step S1, it is preferable to form the helical layer 52 such that the intersection angle α between the fiber bundle 70 and the axial direction of the rotating shaft 18 is 30° to 60°, as shown in Figure 8. As described above, it is easy to form the hoop layer 62 following the helical layer 52.

[0077] When manufacturing a sleeve 40 in the configuration shown in Figure 4, a helical layer formation step S1 involves stacking multiple helical layers 52 to form a laminated helical layer 54, and a hoop layer formation step S2 involves stacking multiple hoop layers 62 to form a laminated hoop layer 64. Furthermore, it is preferable that the total number of hoop layers 62 in the laminated hoop layer 64, N2, is 2 to 8 times the total number of helical layers 52 in the laminated helical layer 54, N1.

[0078] This makes it possible to obtain a sleeve 40 having an inner layer 50 in which displacement of the innermost fiber bundle is further suppressed, and in which strength is effectively improved.

[0079] The following additional information is disclosed regarding the above embodiments.

[0080] (Note 1) The rotating electric machine (10) of the present disclosure comprises a rotor (12) and a stator (14), wherein the rotor has a rotating shaft (18) and a permanent magnet (30) held on the rotating shaft, and the stator has an electromagnetic coil (34) surrounding the permanent magnet, wherein the rotor has a sleeve (40) covering the outer surface of the permanent magnet, the sleeve has a hoop layer (62) formed by hoop winding a fiber bundle (70) of fiber-reinforced resin, the hoop layer includes a plurality of annular portions (66) formed by the annular curvature of the fiber bundle, and the plurality of annular portions are The fiber bundle has a leading ring portion (66A) that is formed relatively first when the fiber bundle is wound continuously, and a trailing ring portion (66B) that is formed following the leading ring portion and adjacent to the leading ring portion in the axial direction of the rotor, and when the direction perpendicular to the longitudinal direction of the fiber bundle is defined as the width direction, the trailing ring portion has an overlapping portion (68) formed by at least one end of the trailing ring portion in the width direction overlapping the leading ring portion in the radial direction of the rotor, and the overlap ratio, which is the ratio of the width direction dimension (OV) of the overlapping portion to the width direction dimension (W) of the fiber bundle, is 20% to 85%.

[0081] In the hoop layer, a portion of the subsequent ring overlaps with the preceding ring by 20% or more, resulting in a sleeve with improved strength. Furthermore, since the overlap ratio is 85% or less, an increase in the sleeve's weight is avoided.

[0082] (Note 2) In the rotating electric machine described in Appendix 1, the superposition ratio may be 30% to 50%.

[0083] (Note 3) In the rotating electric machine described in Appendix 1 or 2, the sleeve has a helical layer (52) formed by helically winding the fiber bundle, the helical layer constitutes an inner layer (50) covering the outer surface of the permanent magnet, and the hoop layer may constitute an outer layer (60) laminated on the helical layer.

[0084] When the sleeve is attached to the rotating shaft, the innermost fiber bundle in the helical layer that makes up the inner layer is less prone to misalignment.

[0085] (Note 4) In the rotating electric machine described in Appendix 3, the intersection angle between the fiber bundle and the axial direction of the rotating shaft in the helical layer may be 30° to 60°.

[0086] In this case, it is easy to stack hoop layers on top of helical layers.

[0087] (Note 5) In the rotating electric machine described in Appendix 3 or 4, the inner layer is a laminated helical layer (54) formed by stacking multiple helical layers, and the outer layer is a laminated hoop layer (64) formed by stacking multiple hoop layers, and the total number of hoop layers (N2) in the laminated hoop layer may be 2 to 8 times the total number of helical layers (N1) in the laminated helical layer.

[0088] This further suppresses misalignment of the innermost fiber bundle. Moreover, it effectively improves the strength of the sleeve.

[0089] (Note 6) In the rotating electric machine described in Appendix 1 or 2, there may be a laminated hoop layer in which multiple hoop layers are stacked.

[0090] (Note 7) In a rotating electric machine described in any one of the appendices 1 to 6, when the diameter of the sleeve before it is mounted on the rotating shaft is D0, and the maximum diameter that the sleeve can expand to is D1, the maximum expansion ratio calculated by the following formula may be 1.2% or more. Maximum diameter expansion rate = {(D1-D0) / D0}×100

[0091] In this case, the elastic deformation range of the sleeve is large. Therefore, for example, damage to the sleeve can be more effectively avoided when attaching it to a rotating shaft.

[0092] (Note 8) In the rotating electric machine described in any one of the appendices 1 to 7, the sleeve has a plurality of ring members (42) arranged along the axial direction of the rotating shaft, and each of the plurality of ring members may have a plurality of annular portions.

[0093] (Note 9) A method for manufacturing a rotor (12) according to the present disclosure is a method for manufacturing a rotor surrounded by a stator (14) in a rotating electric machine (10), having a rotating shaft (18) and a permanent magnet (30) held on the rotating shaft, comprising a hoop layer forming step (S2) in which a bundle of fiber-reinforced resin (70) is wound around the outer surface of the permanent magnet in a hoop winding manner to form a hoop layer (62) including a plurality of annular portions (66) in which the fiber bundle is curved in an annular shape, wherein in the plurality of annular portions, the annular portion formed relatively ahead when the fiber bundle is wound continuously is called a leading annular portion (6 6A) The annular portion formed following the preceding ring portion and adjacent to the preceding ring portion in the axial direction of the rotor is defined as the succeeding ring portion (66B), and the direction perpendicular to the longitudinal direction of the fiber bundle is defined as the width direction. In the hoop layer formation step, an overlapping portion (68) is formed by overlapping at least one end of the succeeding ring portion in the width direction with one end of the preceding ring portion in the width direction in the radial direction of the rotor, and the overlapping ratio, which is the ratio of the width direction dimension (OV) of the overlapping portion to the width direction dimension (W) of the fiber bundle, is set to 20% to 85%.

[0094] As a result, it is possible to obtain a sleeve with improved strength while avoiding an increase in weight.

[0095] (Note 10) In the rotor manufacturing method described in Appendix 9, the overlap ratio may be set to 30% to 50%.

[0096] (Note 11) In the rotor manufacturing method described in Appendix 9 or 10, there is a helical layer forming step (S1) which is performed before the hoop layer forming step and in which a helical layer (52) is formed by winding the fiber bundle in a helical winding manner, wherein the helical layer is an inner layer (50) that covers the outer surface of the permanent magnet, and the hoop layer is an outer layer (60) laminated on the helical layer.

[0097] This results in a sleeve in which the innermost fiber bundle is less likely to shift position when the sleeve is attached to the rotating shaft.

[0098] (Note 12) In the rotor manufacturing method described in Appendix 11, the helical layer may be formed with an intersection angle of 30° to 60° between the fiber bundle and the axial direction of the rotating shaft.

[0099] In this case, it is easy to stack hoop layers on top of helical layers.

[0100] (Note 13) In the rotor manufacturing method described in Appendix 11 or 12, a plurality of helical layers are stacked in the helical layer forming step to form a stacked helical layer (54), and a plurality of hoop layers are stacked in the hoop layer forming step to form a stacked hoop layer (64), and the total number of hoop layers (N2) in the stacked hoop layer is set to 2 to 8 times the total number of helical layers (N1) in the stacked helical layer.

[0101] This further suppresses misalignment of the innermost fiber bundle, resulting in a sleeve with effectively improved strength.

[0102] Furthermore, the present invention is not limited to the disclosure described above, and can take various configurations without departing from the spirit of the invention. [Explanation of Symbols]

[0103] 10... Rotating electric machine 12... Rotor 18... Rotating shaft 30... Permanent magnet 40...Sleeve 42...Ring component 50...Inner layer 52...Helical layer 54…Layered helical layer 60…Outer layer 62...Hoop layer 64...Laminated hoop layer 66...Annular section 66A...Preceding ring section 66B... Subsequent ring portion 68... Superimposed portion 70... Fiber bundle 90... Mounting jig

Claims

1. A rotating electric machine comprising a rotor and a stator, wherein the rotor has a rotating shaft and permanent magnets held on the rotating shaft, and the stator has electromagnetic coils surrounding the permanent magnets, The rotor has a sleeve that covers the outer surface of the permanent magnet, The sleeve has a hoop layer formed by winding a bundle of fiber-reinforced resin fibers in a hoop shape. The hoop layer includes a plurality of annular portions formed by the curvature of the fiber bundle in an annular shape. Each of the annular portions has a leading annular portion that is formed relatively ahead of the fiber bundle when it is wound continuously, and a trailing annular portion that is formed following the leading annular portion and adjacent to the leading annular portion in the axial direction of the rotor. When the direction perpendicular to the longitudinal direction of the fiber bundle is defined as the width direction, the subsequent ring portion has an overlapping portion formed by at least one end of the subsequent ring portion in the width direction overlapping the preceding ring portion in the radial direction of the rotor. A rotating electric machine in which the overlap ratio, which is the ratio of the width dimension of the overlapping portion to the width dimension of the fiber bundle, is 20% to 85%.

2. A rotating electric machine according to claim 1, wherein the superposition ratio is 30% to 50%.

3. In the rotating electric machine according to claim 1, the sleeve has a helical layer formed by helically winding the fiber bundle, A rotating electric machine wherein the helical layer constitutes an inner layer covering the outer surface of the permanent magnet, and the hoop layer constitutes an outer layer laminated on the helical layer.

4. A rotating electric machine according to claim 3, wherein in the helical layer, the intersection angle between the fiber bundle and the axial direction of the rotating shaft is 30° to 60°.

5. In the rotating electric machine according to claim 3, the inner layer is a laminated helical layer formed by stacking a plurality of helical layers, and the outer layer is a laminated hoop layer formed by stacking a plurality of hoop layers. A rotating electric machine in which the total number of hoop layers in the laminated hoop layer is 2 to 8 times the total number of helical layers in the laminated helical layer.

6. A rotating electric machine according to claim 1, wherein the rotating electric machine has a laminated hoop layer in which a plurality of hoop layers are stacked.

7. A rotating electric machine according to claim 1, wherein when the diameter of the sleeve before it is mounted on the rotating shaft is D0, and the maximum diameter that the sleeve can expand to is D1, the maximum expansion ratio, which can be calculated by the following formula, is 1.2% or more. Maximum diameter expansion rate = {(D1-D0) / D0}×100

8. A rotating electric machine according to any one of claims 1 to 7, wherein the sleeve has a plurality of ring members arranged along the axial direction of the rotating shaft, and each of the plurality of ring members has a plurality of annular portions.

9. A method for manufacturing a rotor surrounded by a stator in a rotating electric machine, comprising a rotating shaft and a permanent magnet held on the rotating shaft, The process includes a hoop layer formation step in which a bundle of fiber-reinforced resin is wound around the outer surface of the permanent magnet in a hoop winding manner to form a hoop layer including a plurality of annular portions in which the fiber bundle is curved in an annular shape. A method for manufacturing a rotor, wherein, in a plurality of annular portions, the annular portion formed relatively earlier when the fiber bundle is continuously wound is designated as the leading annular portion, the annular portion formed following the leading annular portion and adjacent to the leading annular portion in the axial direction of the rotor is designated as the succeeding annular portion, and the direction perpendicular to the longitudinal direction of the fiber bundle is designated as the width direction, in the hoop layer formation step, an overlapping portion is formed by overlapping at least one end of the succeeding annular portion in the width direction with one end of the leading annular portion in the width direction in the radial direction of the rotor, and the overlapping ratio, which is the ratio of the width direction dimension of the overlapping portion to the width direction dimension of the fiber bundle, is set to 20% to 85%.

10. A method for manufacturing a rotor according to claim 9, wherein the overlap ratio is 30% to 50%.

11. The method for manufacturing a rotor according to claim 9, comprising a helical layer formation step performed before the hoop layer formation step, wherein the fiber bundle is wound in a helical winding manner to form a helical layer, A method for manufacturing a rotor, wherein the helical layer is an inner layer covering the outer surface of the permanent magnet, and the hoop layer is an outer layer laminated on the helical layer.

12. A method for manufacturing a rotor according to claim 11, wherein the helical layer is formed such that the intersection angle between the fiber bundle and the axial direction of the rotating shaft is 30° to 60°.

13. In the method for manufacturing a rotor according to claim 11 or 12, a plurality of helical layers are stacked in the helical layer forming step to form a stacked helical layer, and a plurality of hoop layers are stacked in the hoop layer forming step to form a stacked hoop layer, A method for manufacturing a rotor, wherein the total number of hoop layers in the laminated hoop layer is 2 to 8 times the total number of helical layers in the laminated helical layer.

Images