Insertion member for rotating electrical machine

Abstract

The present disclosure provides an embedded component for a rotating motor that can improve the bonding strength with the motor housing. A plurality of protrusions are formed on the outer peripheral surface of the embedded component that is roughly cylindrical. In a cut surface obtained by cutting the embedded component, a solid part area and a non-solid part area are divided. When the value representing the proportion of the solid part area on the line segment is set as the solid part ratio, a graph on which the values of the plurality of solid part ratios are sequentially plotted is set as a solid part total graph. In the average solid part total graph obtained based on a plurality of cross sections, when the position where the average solid part ratio is 0 is set as the top end of the graph and the position where the average solid part ratio exceeds 0.98 for the first time is set as the base end of the graph, the average maximum height of the protrusion as the distance from the top end of the graph to the base end of the graph is not less than 0.08% of the outer diameter of the embedded component.

Description

Technical Field

[0001] The present invention relates to an insert component for a rotating electrical machine. Background Art

[0002] Traditionally, aluminum alloys have been used as structural members in motor housings. Furthermore, in the motor housing, high-strength, cylindrically shaped members made of iron-based materials are sometimes used as inserts in the stator housing to enhance strength. In this regard, proposals have been made to improve the retention of the inserts relative to the motor housing by providing recesses and projections on their outer circumferences (see, for example, Patent Documents 1, 2, and 3).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2001-169500

[0006] Patent Document 2: Japanese Patent Application Laid-Open No. 2011-101513

[0007] Patent Document 3: Japanese Patent Application No. 6655560

[0008] When forming a motor housing from an aluminum alloy, the aforementioned insert member is sometimes cast into the housing. After casting, the inner circumference of the insert member is machined to fit over the outer circumference of the stator, allowing the insert member to serve as a stator retainer. Insufficient bonding strength between the motor housing and the insert member can cause the insert member to shift relative to the motor housing, potentially causing motor shaft oscillation, resulting in reduced output due to increased friction, and reduced durability due to increased vibration. Summary of the Invention

[0009] The technology of the present invention has been accomplished in view of the above-mentioned circumstances, and an object of the present invention is to provide an insert member for a rotating electric machine capable of improving the joining strength with the motor case.

[0010] To solve the above-mentioned problems, the present invention adopts the following configuration. An insert component for a rotating electric machine, one aspect of the present invention, is a substantially cylindrical insert component to be cast into an aluminum alloy motor housing of the rotating electric machine, wherein a plurality of protrusions are formed on the outer peripheral surface of the insert component. In a single cut plane, the insert component is divided into a solid portion region and a non-solid portion region within a predetermined axial length. The single cut plane is one of the cut planes that appear on either side of the central axis when the insert component is bisected along the axial direction by an imaginary plane containing the central axis of the insert component. The solid portion region is a region where the protrusions overlap with a line segment parallel to the inner peripheral surface of the insert component when the line segment is overlapped with the single cut plane. The non-solid portion region is a region where the protrusions do not overlap with a line segment parallel to the inner peripheral surface of the insert component when the line segment is overlapped with the single cut plane. A value representing the ratio of the solid portion region to the line segment within the predetermined axial length is defined as a solid portion ratio, and the line segment is defined as a solid portion ratio. In the one cut surface of the component, measurement points are obtained by moving at predetermined intervals along the height direction of the protrusion from the tip toward the base end side of the protrusion, and a graph on which the values of the solid portion ratios of the measurement points are sequentially plotted, with the solid portion ratios represented on the horizontal axis and the distance from the tip in the height direction represented on the vertical axis as the measured height is defined as a solid portion total graph. The average of the solid portion ratios at the measurement points obtained through the plurality of cut surfaces is defined as an average solid portion ratio. The solid portion total graph on which the average solid portion ratios are plotted is defined as an average solid portion total graph. In the average solid portion total graph, the position where the average solid portion ratio is 0 is defined as the tip end on the graph, the position where the average solid portion ratio first exceeds 0.98 when sequentially plotted from the tip end side toward the base end side is defined as the base end on the graph, and the distance from the tip end on the graph to the base end on the graph is defined as the average maximum height of the protrusion. When this average maximum height of the protrusion is defined as 0.08% or more of the outer diameter of the insert component.

[0011] Furthermore, in the insert member, the average maximum height of the protrusions may be formed within a range of 0.08% to 1% of the outer diameter of the insert member.

[0012] In addition, the embedded component for the rotating motor may be constructed as follows: in the average solid portion total diagram, the total value of the average solid portion ratio in the range from the central position of the average maximum height of the protrusion to the base end portion on the diagram, excluding the position of the base end portion on the diagram, is greater than the total value of the average solid portion ratio in the range from the central position of the average maximum height of the protrusion to the top end portion on the diagram, excluding the position of the top end portion on the diagram.

[0013] In addition, it may also be that the embedded component for the rotating motor includes two or more measurement points plotted on the average solid portion total graph, and the difference in the average solid portion ratio of the two or more measurement points is less than 0.10 and the difference in the measured height of the two or more measurement points is greater than 0.05 mm.

[0014] In addition, the embedded component for the rotating motor may be constructed as follows: the multiple average solid portion ratios plotted on the average solid portion total graph have a maximum peak point where the value of the average solid portion ratio is extremely large and a minimum peak point where the value of the average solid portion ratio is extremely small, and the position of the maximum peak point appears at a position closer to the top end side of the graph than the position of the minimum peak point.

[0015] Furthermore, in the average substantial portion total graph, the value of the average substantial portion ratio at the minimum peak point may be 0.08 or greater.

[0016] Furthermore, in the average substantial portion total graph, a difference between a value of the average substantial portion ratio at the maximum peak point and a value of the average substantial portion ratio at the minimum peak point may be greater than or equal to 0.02 and less than or equal to 0.20.

[0017] Furthermore, in the average substantial portion total graph, the value of the average substantial portion ratio at the maximum peak point may be 0.50 or less.

[0018] The protrusion may be formed on only a partial region of the outer peripheral surface of the insert member.

[0019] Effects of the Invention

[0020] According to the present invention, it is possible to provide an insert member for a rotating electrical machine capable of improving the joining strength with the motor case. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is an overall view of an insert member for a rotating electrical machine according to an embodiment and an enlarged view of a portion of an outer peripheral surface of the insert member for a rotating electrical machine.

[0022] Figure 2 This is a cross-sectional view showing an example of a predetermined cut surface of the insert member for the rotating electrical machine according to the embodiment.

[0023] Figure 3 This is an average solid portion total graph for explaining the relationship between the measured height and the average solid portion ratio of an embedment member for a rotating electrical machine in one example of an embodiment.

[0024] Figure 4 FIG. 1 is a graph showing an average solid portion of an embedded component for a rotating electrical machine in one example of an embodiment.

[0025] Figure 5 FIG. 1 is a graph showing an average solid portion of an embedded component for a rotating electrical machine in one example of an embodiment.

[0026] Description of Reference Numerals

[0027] 1: Embedded components for rotating motors;

[0028] 10: protrusion;

[0029] 20: line segment;

[0030] 30: protrusion after aggregation;

[0031] C: The center axis of the embedded component. DETAILED DESCRIPTION

[0032] The following describes embodiments of the present invention with reference to the accompanying drawings. Unless otherwise specified, the configurations described in the following embodiments are not intended to limit the technical scope of the invention to these configurations. The configurations and combinations thereof in the following embodiments are merely examples, and additions, omissions, substitutions, and other modifications may be made as appropriate without departing from the spirit of the present invention.

[0033] <Implementation Method>

[0034] [Structure / Manufacturing method]

[0035] Figure 1 This figure shows an overall view of an insert component 1 for a rotating electrical machine (hereinafter referred to as "insert component 1") according to an embodiment, as well as an enlarged view of a portion of the outer peripheral surface of the insert component 1. In this embodiment, the direction along the central axis C of the insert component 1 is referred to as the axial direction, and the direction perpendicular to the axial direction and extending from the central axis C toward the outer peripheral surface of the insert component 1 is referred to as the radial direction. Furthermore, the direction around the central axis C along the outer peripheral surface of the insert component 1 is referred to as the circumferential direction. These axial, radial, and circumferential directions are merely directions used to indicate the relative positional relationships of the various components in the insert component 1.

[0036] The embedded component 1 of this embodiment is, for example, a cast iron part formed into a roughly cylindrical shape with the central axis C as the center, and a plurality of protrusions 10 are formed on its outer peripheral surface (surface). The rotating electric machine to which the present invention is applied is, for example, a motor for electric vehicles, etc. However, the rotating electric machine to which the present invention is applied is not limited to this. The outer diameter OD of the embedded component 1 in this embodiment is formed in the range of 150 mm to 300 mm, but it can also be appropriately changed according to the application. In addition, the outer diameter OD is a value equivalent to the distance between two parallel planes when the embedded component 1 is placed between two parallel planes in a manner such that the central axis C of the embedded component is parallel to the two planes and the top end 11 of the protrusion 10 located on the outer peripheral surface of the embedded component 1 is in contact with the two parallel planes respectively.

[0037] A rotating electric machine is constructed, for example, to include components such as a rotating shaft, a rotor, a stator, a motor housing, and bearings. The motor housing has a cylindrical portion formed by hollowing out the interior. The stator is generally formed of an electromagnetic steel plate or the like, and is fitted into the inner circumference of the cylindrical portion. Here, the embedded component 1 is cast into the inner circumference of the motor housing made of an aluminum alloy and used. As a result, the motor housing and the embedded component 1 become a composite structure in which at least a portion of the outer circumference of the embedded component 1 is covered with aluminum alloy. In addition, when the stator is embedded in the inner circumference of the embedded component 1, the stator is heat-fitted. However, the linear expansion coefficient of the stator material is close to that of the embedded component 1. Therefore, even when heat is generated during operation of the motor, the fitting strength between the stator and the embedded component 1 is ensured.

[0038] Generally speaking, the operating temperature of the motor is -30℃~150℃. In addition, the material used for the stator is generally electromagnetic steel plate. When the embedded component 1 is made of 10.0×10 －6 / K or above and 13.0×10 －6 When the insert member 1 is formed of a material with a linear expansion coefficient of 1 / K or less, the linear expansion coefficients of the stator and the insert member 1 to be fitted are similar. This helps maintain a high fitting strength between the outer periphery of the stator and the inner periphery of the insert member 1 even after the stator is fitted into the insert member 1 cast in the motor housing.

[0039] The material of the insert member 1 is not particularly limited as long as it has sufficient strength compared to the aluminum alloy used for the motor housing and has a linear expansion coefficient within the above range. Typically, flake graphite cast iron such as a material equivalent to JIS FC250 can be used, taking into account manufacturability and processability.

[0040] The method for forming the protrusion 10 of the insert member 1 is not particularly limited, and for example, centrifugal casting can be used. Alternatively, the protrusion 10 of the insert member 1 can be formed by machining a cast iron cylinder.

[0041] Figure 2 This is a cross-sectional view showing an example of a predetermined cutting surface of the embedded component 1 of the embodiment. The predetermined cutting surface in this embodiment is a cutting surface that appears one of the cutting surfaces on both sides of the center axis C when the embedded component 1 is cut in two along the axial direction using an imaginary plane including the center axis C of the embedded component 1. The axial length of one cutting surface is greater than or equal to the length d1 described later. Figure 2 As an example of a prescribed cutting surface, the figure shows Figure 1 In addition, Figure 2 The reference numeral 40 shown in the figure denotes the inner peripheral surface of the embedded member 1. Hereinafter, it is referred to as "inner peripheral surface 40". Figure 2 Next, the plurality of protrusions 10 included in the insert member 1 of the present embodiment will be described.

[0042] The protrusion 10 is a portion of the insert component 1 and is formed on the outer circumferential surface of the insert component 1. Multiple protrusions 10 may be arranged in the axial and circumferential directions with discontinuous and irregular (random) arrangement and density, or they may be arranged in a continuous and regular manner. The protrusion 10 has a tip 11 and a base 12, and is formed so as to project radially outward from the base 12 toward the tip 11.

[0043] Furthermore, the outer peripheral surface of the insert member 1 may be processed to limit the location where the plurality of protrusions 10 are formed to a portion or to remove a portion of the plurality of protrusions 10. Thus, the plurality of protrusions 10 may be formed only on a portion of the outer peripheral surface of the insert member 1.

[0044] The protrusion 10 is sometimes formed by centrifugal casting while being cast with centrifugal force. In this case, the top 11 of the protrusion 10 is formed with respect to the inner circumference of the mold. Therefore, if the inner circumference of the mold is a perfect circle, the distance between the top 11 and the center axis C of the embedded component 1 is approximately the same, while the distance between the base 12 and the center axis C may not be consistent. Therefore, when using the solid portion total diagram described later to deduce the height of the protrusion 10, the height of the protrusion 10 is measured with respect to the top 11 as the reference. However, the method of forming the protrusion 10 is not limited to this. For example, the protrusion 10 can also be formed by performing mechanical processing such as cutting on the outer circumference of the cylindrical component.

[0045] The shape of the protrusion 10 is not particularly limited. For example, the protrusion 10 may have a continuous spiral shape or a continuous ring shape along the circumferential direction. For example, the protrusion 10 may be formed into a spiral or ring shape by directly machining the outer circumference of the insert component 1, such as by cutting. The shape of the protrusion 10 may be any shape that provides an effect in the physical cutting test, tensile simulation, and shear simulation described later.

[0046] [Entity Ratio]

[0047] The protrusion 10 of the embedded component 1 is divided into a solid area 21 and a non-solid area 22. Figure 2 As shown, the solid portion region 21 and the non-solid portion region 22 are determined based on whether or not a line segment 20 having a length d1 (an example of a "predetermined axial length" in the present invention) overlaps with the protrusion 10 when the line segment 20 is aligned with the predetermined cutting plane. More specifically, within the range of length d1, the region where the line segment 20 overlaps with the protrusion 10 is defined as the solid portion region 21, and the region where the line segment 20 does not overlap with the protrusion 10 is defined as the non-solid portion region 22. It should be noted that the line segment 20 is a hypothetical line segment parallel to the inner circumferential surface 40 (that is, parallel to the central axis C) within the predetermined cutting plane and is provided to facilitate the identification of the solid portion region 21 and the non-solid portion region 22.

[0048] The solid portion ratio is a value indicating the ratio of the solid portion region 21 formed within the range of the length d1. Figure 2 By moving in the direction of arrow A20 (radially from the tip 11 side to the base 12 side) at a predetermined interval, the length of the solid portion region 21 at the measurement height of any measurement point can be obtained, wherein the measurement height is the radial distance from the tip 11. At this time, the ratio of the length obtained by summing the lengths of the solid portion region 21 at any measurement height to the length d1 is called the "solid portion ratio." The same operation is performed on multiple cross sections, and the solid portion ratios of the protrusion 10 in each cut surface are summarized. The solid portion ratios at the measurement height of each measurement point are averaged, thereby obtaining the average value of the solid portion ratios based on multiple cross sections at the arbitrary measurement height, that is, the average solid portion ratio.

[0049] [Entity Department Total Chart]

[0050] like Figure 2As shown, by moving a line segment 20 toward the base end 12 (along the direction of arrow A20) at a predetermined pitch, the solid portion ratio is repeatedly obtained until the solid portion ratio reaches 1.00. The obtained solid portion ratios are plotted on a graph, thereby creating a graphical representation of the shapes of multiple protrusions 10 appearing within a predetermined cut surface. This is referred to as a "solid portion total graph." The solid portion total graph shows the distance from the tip 11 of the protrusion 10 in the height direction, i.e., the measured height, on the vertical axis, and the solid portion ratio on the horizontal axis. Furthermore, by calculating the solid portion ratio across multiple predetermined cut surfaces and creating an averaged solid portion total graph, the formation state of the protrusion 10 in the embedded component 1 can be averaged. In this case, the reference point in the height direction is set to "the tip 11 of the most protruding protrusion 10 within the range of length d1 (predetermined axial length)" in all predetermined cut surfaces, and the pitch at which the line segment 20 is moved is kept constant. Thus, even in multiple predetermined cutting surfaces, the measured height can be uniquely determined. In addition, in this embodiment, the protrusions determined by the shape of the figure appearing in the average solid portion total graph are referred to as "summed protrusions" in the average solid portion total graph. As an example of the embedded component 1 of this embodiment, Figure 3 The following average solid area total graph is shown: the average solid area ratios that can be obtained intermittently from six predetermined cut surfaces of a certain sample are plotted sequentially with a predetermined interval of 0.05 mm and a length d1 of 14.7 mm. Figure 3 As shown, the protrusions determined by the shape of the graph appearing in the average solid portion total graph are shown as the summarized protrusions 30 .

[0051] [Measurement method]

[0052] Below, use Figure 2 , the measurement method of the solid part area 21 and the non-solid part area 22 is described. First, the adjustment method of the sample for measurement is described. The embedded component 1, which includes the center axis C and is cut in the axial direction, is further cut into a size that can be resin-embedded and polished, and the resin is embedded with one cut surface to be measured for the solid part ratio facing downward. After the resin is solidified, one cut surface side is polished using water-resistant sandpaper in running water. At this time, the grit number of the water-resistant sandpaper is replaced in the order of #220, #400, #800, #1000, and #1500. After the polishing is completed, the solid part ratio is measured. The observation surface after the polishing is equivalent to the specified cut surface.

[0053] In this embodiment, a digital microscope RX-100 manufactured by Hirox Co., Ltd. is used to measure the solid portion ratio. Furthermore, a 20x or 50x objective lens magnification is used during measurement, and a grid and automatic width tool based on the software included with the microscope are used. The measurement sample, polished as described above, is placed so that the inner peripheral surface 40 of the embedded component 1 is parallel to the horizontal axis of the grid displayed on the observation monitor. The measurement sample is then moved parallel to a position where the outer peripheral surface of the embedded component 1 can be observed. Next, the automatic width tool is used to measure the measurement sample in the horizontal direction. Because the measurement using the automatic width tool is an automatic measurement using grayscale concentration, the grayscale concentration is adjusted each time to appropriately identify the embedded component area corresponding to the solid portion area 21 and the resin area corresponding to the non-solid portion area 22. The length of the solid portion area 21 at any measurement height is measured each time the measurement is made by moving the measurement sample at a specified interval. Line segment 20 in this embodiment represents the measurement position of the automatic width tool. By moving the wire segment 20 along the radial direction of the insert member 1 from the distal end 11 toward the proximal end 12, the axial length of the solid portion 21 at any measurement height relative to the distal end 11 can be measured. In this case, the wire segment 20 is moved in predetermined intervals of 0.05 mm or 0.025 mm from the distal end 11 of the protrusion 10 that protrudes most within the length d1 toward the proximal end 12 within a single cut plane.

[0054] exist Figure 2 , the figure shows the case where line segment 20 is at position 20a and the case where line segment 20 is at position 20b. When line segment 20 is at the measurement height indicated by position 20a, line segment 20 overlaps with the most protruding tip portion 11 within length d1. Using this as a reference, line segment 20 is moved in the direction of arrow A20 (towards the base end portion 12). Position 20b is an example of the measurement height obtained by repeatedly moving line segment 20 a predetermined number of times. When line segment 20 is at position 20b, it can be said that the embedded component 1 has a solid portion region 21 indicated by the dashed line and a non-solid portion region 22 indicated by the solid line within line segment 20. The measurement is terminated when line segment 20 is moved along arrow A20 from the position where the solid portion ratio first exceeds 0.98 (described later), and when line segment 20 is further moved along arrow A20 from the position where the solid portion ratio first exceeds 0.98, so that the entire length of line segment 20 within length d1 is within solid portion region 21 (that is, when the solid portion ratio reaches 1.00).

[0055] [Parameters of the average entity total graph]

[0056] Figure 3 , which shows a graph of the average solid portion totals in which the average solid portion ratios based on a certain sample are plotted. Figure 2 and Figure 3 As shown, in the average solid area total graph, the position corresponding to "the most prominent tip 11 of the protrusion 10 among the multiple protrusions 10 within the range of length d1" is referred to as the "top end in the graph." The top end in the graph corresponds to the tip end of the aforementioned aggregated protrusions 30. The measured height at the top end in the graph is 0 mm, and the average solid area ratio is 0. Furthermore, "the position where the average solid area ratio first exceeds 0.98 among the points plotted on the average solid area total graph" is referred to as the "base end in the graph."

[0057] Figure 3 The maximum peak and minimum peak are shown in the average body total graph. The graph obtained by connecting the measurement points plotted on the average body total graph with lines is called the "average body curve". The maximum peak represents the average body ratio at the maximum peak point among the peak points in the average body curve, and the minimum peak represents the average body ratio at the minimum peak point among the peak points in the average body curve plotted on the average body total graph. Figure 3 In the example of the average total body portion graph shown, the absolute value of the height measured from the top of the graph to the maximum peak point is 0.20 mm, with a maximum peak value of 0.45. The absolute value of the height measured from the top of the graph to the minimum peak point is 0.45 mm, with a minimum peak value of 0.30. In this case, the maximum peak point appears closer to the top of the graph than the minimum peak point in the measured height direction.

[0058] Figure 3 The average maximum height h1 of the aggregated protrusions 30 shown is the distance from the top end to the base end on the vertical axis of the average total solid area graph. Because the solid area ratio at each measurement point on the total solid area graph is measured from the top end 11 of the protrusion 10 toward the bottom center axis C, the measured height at each measurement point is represented as a negative value. This is also true for the average total solid area graph calculated from multiple total solid area graphs. However, the actual average maximum height h1 of the protrusion 10 is the absolute value of the value on the vertical axis of the average total solid area graph.

[0059] The protrusion 10 in this embodiment is formed so that the maximum peak value in the average solid portion total graph is ≤0.50. Thus, the protrusion 10 is formed so that the base end portion 12 side is wider than the top end portion 11 side. Therefore, when the embedded component 1 is cast with aluminum alloy, the aluminum alloy flowing into the mold can easily flow toward the base end portion 12 side of the protrusion 10, thereby preventing the generation of gaps in the joint portion between the embedded component 1 and the motor housing. In addition, when a load is applied to the protrusion 10, the protrusion 10 is not easily broken. The shape of the top end portion 11 of the protrusion 10 is not particularly limited, as long as it is formed so that the maximum peak value is ≤0.50. For example, the top end portion 11 can also be formed in a circular, angular, or flat shape.

[0060] Alternatively, multiple protrusions 10 may be formed so that the maximum peak point of the protrusions 30 summarized in the average total volume graph appears closer to the top end than the minimum peak point. Furthermore, in the average total volume graph, the sum of the average volume ratios from the center of the average maximum height h1 of the summarized protrusions 30 to the base end on the graph, excluding the base end, may be greater than the sum of the average volume ratios from the center of the average maximum height h1 of the summarized protrusions 30 to the top end on the graph, excluding the top end. Here, if the center of the average maximum height h1 of the summarized protrusions 30 coincides with the point at which the average volume ratios are measured, the center of the average maximum height h1 of the summarized protrusions 30 is included in the top end on the graph. This allows determination of whether the top end side of the summarized protrusions 30 is thinner than the base end side on the graph.

[0061] Alternatively, the maximum peak point in the combined protrusions 30 may be located closer to the base end in the figure than the top end in the figure, where the height is measured to be 0 mm. This prevents the maximum peak point from forming at the top end in the combined protrusions 30, thereby preventing the top end 11 of the protrusion 10 from being damaged or broken.

[0062] Alternatively, with respect to the average solid portion ratio, among the multiple measurement points plotted on the average solid portion total graph, two or more measurement points are included within a range where the difference in the average solid portion ratios of the two or more measurement points is less than 0.10 and the difference in the measured heights of the two or more measurement points is greater than 0.05 mm. Figure 3The plot of points N1 to N3 is shown as an example. The values plotted at points N1 to N3 are plotted within a range where the maximum difference in average solid ratio is 0.007 and the maximum difference in measured height is 0.10 mm. Thus, when the difference in average solid ratio at two or more measured points is 0.10 or less, and the difference in measured height at two or more measured points is 0.05 mm or more, the slope of the average solid curve in the average solid summation plot becomes steeper. Thus, in the portion of the average solid curve where the slope is steep in the aggregated portion of the protrusions 30 in the average solid summation plot, on average, a portion of the plurality of protrusions 10 is formed substantially perpendicular to the outer peripheral surface of the insert component 1. Thus, even in a configuration where the aggregated protrusions 30 do not have a maximum peak point, having a portion of the aggregated protrusions 30 where the slope is steep can improve the bonding strength between the motor housing and the insert component 1.

[0063] In the average solid portion total graph, the difference between the maximum peak and the minimum peak can also be greater than 0.02 and less than 0.20. If the difference between the maximum peak and the minimum peak is less than 0.02, the bonding strength between the motor housing and the embedded component 1 may be reduced compared to a difference of greater than 0.02. Furthermore, if the difference between the maximum peak and the minimum peak is greater than 0.20, when the embedded component 1 is cast with aluminum alloy, the aluminum alloy flowing into the mold may have difficulty flowing to the base end 12 side of the protrusion 10, or a portion of the formed protrusion 10 may be broken or damaged. In contrast, by setting the difference between the maximum peak and the minimum peak to greater than 0.02 and less than 0.20, damage to the protrusion 10 can be prevented, and high bonding strength can be ensured.

[0064] In the average total solid area graph, the minimum peak value may be 0.08 or greater. If the minimum peak value is less than 0.08, it may be difficult to form the protrusions 10 during the manufacturing process of the insert component 1, and the protrusions 10 may be easily damaged. In contrast, by setting the average total solid area ratio of the minimum peak value to 0.08 or greater, the number of protrusions 10 can be prevented from being too small. Furthermore, the lack of strength caused by overly thin protrusions 10 is eliminated, making the protrusions 10 less likely to break.

[0065] In the average solid portion total graph, the maximum peak value may be less than 0.50, and more preferably less than 0.45. In the case where the maximum peak value is greater than 0.50, when the embedded component 1 is cast with an aluminum alloy, the aluminum alloy flowing into the mold may have difficulty spreading between the multiple protrusions 10. In particular, the aluminum alloy may have difficulty spreading toward the base end portion 12. In addition, there is a possibility that the edge of the protrusion 10 may be damaged near the position where the value of the average solid portion ratio is the maximum peak point, or the protrusion 10 may be easily broken near the position where the value of the average solid portion ratio is the minimum peak point. In contrast, when the maximum peak value is less than 0.50, more preferably when the maximum peak value is less than 0.45, these problems can be prevented.

[0066] [Test / Simulation]

[0067] The embedded components 1 of Examples 1 to 13 of the present invention and the embedded components of the comparative examples were evaluated through testing and simulation using samples. Specifically, the embedded components of the examples and comparative examples (hereinafter referred to as examples, etc.) were subjected to measurement and evaluation of various parameters, physical cutting tests, tensile simulations, and shear simulations.

[0068] [Measurement / Evaluation of Various Parameters]

[0069] Various parameters of the embedded components of the various examples were measured and evaluated. Table 1 shows the results for each item of the embedded components of the examples. Furthermore, for the embedded components of the examples, the prescribed spacing was set to 0.05 mm or 0.025 mm, the length d1 was set to 14.7 mm or 5.57 mm, and a high objective magnification was selected when the average maximum height h1 of the protrusion was small, to produce an average solid portion total graph. It should be noted that Table 1 shows the various parameters of the embedded component without the protrusion 30 as a reference example.

[0070] [1. Ratio of the average maximum height h1 of the protrusion to the outer diameter OD]

[0071] In Item 1, the average maximum height h1 of the protrusions 30 in the sum of the average solid portion plots in each Example, etc., was calculated as a percentage relative to the outer diameter OD of the insert component. This confirmed whether the summed protrusions 30 in the Examples, etc., were formed within a range of 0.08% to 1% of the outer diameter OD of the insert component.

[0072] [2. Is the base end portion thicker than the tip end portion?]

[0073] In Item 2, based on the average total solid area graph in each Example, etc., a determination is made as follows: whether the sum of the average solid area ratios within the range from the center position of the average maximum height h1 of the aggregated protrusions 30 to the base end in the figure, excluding the base end position in the figure, is greater than the sum of the average solid area ratios within the range from the center position of the average maximum height h1 of the aggregated protrusions 30 to the top end in the figure, excluding the top end position in the figure. Based on the average total solid area graph in each Example, if the base end side in the figure is larger than the top end side in the figure (that is, if the base end side in the figure is thicker), a value of "0" is assigned; if the base end side in the figure of the aggregated protrusions 30 is equal to or smaller than the top end side in the figure, a value of "×" is assigned.

[0074] [3. Whether the measurement points include two or more points where the difference in average solid area ratio is 0.10 or less and the difference in measurement height is 0.05 mm or more]

[0075] Item 3 determines whether the average solid area ratios plotted on the average solid area total graph in each example, etc., include two or more measurement points where the difference in average solid area ratio is 0.10 or less and the difference in measured height is 0.05 mm or more. If a point meeting these conditions is included, the value is marked as "0"; if not, the value is marked as "X."

[0076] [4. Whether there are maximum peak points or minimum peak points]

[0077] In Item 4, when there are a maximum peak point and a minimum peak point in the average entity total graph in each embodiment, etc., and the maximum peak point is located closer to the top end portion side on the graph than the center position of the average maximum height h1 of the protrusion and closer to the top end portion side on the graph than the minimum peak point, it is set to "0". When the maximum peak point is located closer to the top end portion side on the graph than the center position of the average maximum height h1 of the protrusion and closer to the base end portion side on the graph than the minimum peak point, or when no peak point appears on the average entity total graph, it is set to "×".

[0078] [5. Minimum peak value] [6. Difference between maximum peak value and minimum peak value]

[0079] In item 5, the minimum peak value was determined based on the averaged total graph of the substantial portion in each example, etc. In item 6, the difference between the maximum peak value and the minimum peak value was determined based on the averaged total graph of the substantial portion in each example, etc.

[0080] [7. Location of the maximum peak point]

[0081] In Item 7, based on the average entity total graph in each embodiment, when the maximum peak point is located closer to the base end side of the graph than the top end on the graph, it is set to "0", and when no peak point appears on the average entity total graph, it is set to "×".

[0082] [Table 1]

[0083]

[0084] The embedded components of Examples and the like measured as shown in Table 1 were further subjected to a physical cutting test, a tensile simulation, and a shear simulation. The test and simulation will be described below.

[0085] [Entity cutting test]

[0086] In the physical cutting test, the embedded components described in the examples and other examples were cast into an aluminum alloy equivalent to the motor housing. Furthermore, while the embedded components were bonded to the aluminum alloy, test pieces were cut out with four 20 mm sides to confirm the bond strength. In this case, if the bond between the embedded components and the aluminum alloy was maintained in all six test pieces obtained from the physical cutting test, the bond was designated A0. If the embedded components and the aluminum alloy separated in some of the test pieces, the bond was designated B0. If the embedded components and the aluminum alloy separated in all six test pieces obtained from the physical cutting test, the bond was designated C0. The results are shown in Table 4, and details are described below.

[0087] [Stretch simulation]

[0088] The aluminum alloy located on the outside of the embedded component will undergo solidification shrinkage and thermal shrinkage during the cooling process after die-casting, thereby tightening the protrusion formed on the outer peripheral surface of the embedded component, and the embedded component is bonded to the aluminum alloy. Usually, when the embedded component cast with aluminum alloy is cut out from the cast state, part of the tightening force will be released from the bonded state. Therefore, it is difficult to measure the actual bonding strength. In contrast, in this simulation, a protrusion is formed in a shape that aggregates multiple protrusions into one based on the average solid part total diagram. Through a simulation based on CAE (Computer Aided Engineering) analysis, the radial displacement difference of the protrusion when the expansion amount is different due to the difference in linear expansion coefficient between the aluminum alloy and the cast iron embedded component is evaluated. At this time, as temperature conditions, the evaluation is performed under the conditions of high temperature: 150°C and medium temperature: 85°C. As a representative example, refer to Figure 3 To explain.

[0089] As mentioned above, Figure 3The figure shows a combined protrusion 30, which is a shape that combines multiple protrusions 10 into a single shape based on the average solid portion summation diagram. In the average solid portion summation diagram, the combined protrusion 30 is divided into a region where the longitudinal axis is considered to be the radial direction of the embedded component 1 and the transverse axis is considered to be the axial direction of the embedded component 1. The combined protrusion 30 is reduced (referred to as a "reduced combined protrusion") while maintaining its longitudinal length and reducing its transverse length in the average solid portion summation diagram to 1 / 2 of that length. Furthermore, the combined protrusion 30 is rotated about the longitudinal axis of the average solid portion summation diagram as the axis of symmetry. This allows the model of the protrusion that combines the protrusion shapes of the embedded component 1 into a single shape (referred to as a "model protrusion"). The reason for reducing the transverse length of the combined protrusion 30 to 1 / 2 of that length is to define a model protrusion that combines the protrusion shapes within a range of length d1 into a single shape, and to use this model protrusion for simulation. The thickness of the reduced aggregated protrusion can be calculated by converting the transverse length of the reduced aggregated protrusion to its length d1. In this simulation, a model of an insert component was created, with two model protrusions cast from aluminum alloy and formed on the outer circumference. CAE analysis simulated radial displacement of the model under the aforementioned temperature conditions, resulting in a tensile evaluation simulating thermal expansion. The difference in radial displacement between the aluminum alloy and the insert component and the ratio of this displacement difference to the average maximum height h1 of the protrusions were used to determine the thickness, as shown in Table 2.

[0090] [Table 2]

[0091] determination Decision symbol The radial displacement difference is less than 10 μm A1 The displacement difference in the radial direction is less than 50% of the average maximum height h1 of the protrusion B1 The radial displacement difference exceeds 50% of the average maximum height h1 of the protrusion C1

[0092] [Shear simulation]

[0093] In the shear simulation, a model of an insert component with a dummy protrusion formed on its outer circumference, cast from aluminum alloy, was created. Shear evaluation was performed assuming an axial torque applied to the insert component. In this simulation, shear loads assuming shear in both the axial and circumferential directions were applied to the dummy protrusion, cast from aluminum alloy. The shear load was assumed to be a load equivalent to the motor shaft torque acting on the outer circumference of the insert component. The radial displacement difference between the aluminum alloy and the insert component was determined based on the ratio of this displacement difference to the average maximum height h1 of the protrusion, as shown in Table 3.

[0094] [Table 3]

[0095] determination Decision symbol The displacement difference in the radial direction is less than 0.1% of the average maximum height h1 of the protrusion A2 The displacement difference in the radial direction is 0.1% or more and less than 0.5% of the average maximum height h1 of the protrusions. B2 The displacement difference in the radial direction is 0.5% or more of the average maximum height h1 of the protrusion C2

[0096] Table 4 shows the results of the physical cutting test, tensile simulation, and shear simulation measured as described above, and the comprehensive evaluation based on these results.

[0097] [Table 4]

[0098]

[0099] In the comprehensive judgment, if the physical cutting test, tensile simulation, and shear simulation are all A judgments, it is set as comprehensive judgment A. If any of the physical cutting test, tensile simulation, and shear simulation has a C judgment, it is set as comprehensive judgment C. In the case of other results, it is set as comprehensive judgment B.

[0100] Based on the above results, and with reference to the Examples, it has been confirmed that the average maximum height h1 of the protrusions 30 after aggregation is preferably within a range of 0.08% to 1% of the outer diameter OD, and more preferably, the average maximum height h1 of the protrusions 30 after aggregation is 0.26% or more of the outer diameter OD. Furthermore, it has been confirmed that when the average maximum height h1 of the protrusions 30 after aggregation is less than 0.26%, the bonding strength between the insert member and the motor case decreases.

[0101] Based on the above results, a comparison of Examples 1 to 5, Example 8 with Examples 6, Example 7, Examples 9 to 13, and the Comparative Examples confirmed that when the minimum peak value is 0.08 or greater, excellent results are achieved in tensile and shear simulations even under high temperature conditions. Similarly, it was confirmed that the difference between the maximum peak value and the minimum peak value is preferably 0.02 or greater.

[0102] In view of these results, it can be said that the insert member 1 of the present embodiment can prevent the insufficient joining strength with the motor case.

[0103] Next, Example 13, Example 11, and Example 2 in the above-mentioned tests / simulations are given as examples, and the average solid portion total diagram and the configuration of the embedded member 1 in each example are described. Figure 4 This is a graph showing the average total solid portion of the insert member 1 in Example 13 of the present embodiment. Figure 5 This is a graph showing the average total solid portion of the insert member 1 in Example 11 of the present embodiment. Figure 3 This is a graph showing the average solid portion of the embedded component 1 in Example 2 of this embodiment. Figure 4 , refer to Example 11 Figure 5 , refer to Example 2 Figure 3 The average solid portion total diagram and the embedded component 1 in each example of this embodiment are described separately in a manner.

[0104] Figure 4The figure shows the reduced aggregated protrusion 301 of Example 13 after the aggregated protrusion 30 is reduced in such a way that the length in the horizontal axis direction of the average solid portion total graph becomes 1 / 2 of the length. In view of the model protrusion based on the reduced aggregated protrusion 301, it can be confirmed that the reduced aggregated protrusion 301 is the same as the Figure 4 In the embedded component 1 related to the average solid portion total diagram shown, the protrusions 30 after aggregation have a cross-sectional shape that is roughly triangular and protrudes in the radial direction, and are formed to extend from the top end 11 to the base end 12. In addition, the protrusions 10 formed on the embedded component 1 can exist individually, or they can be formed continuously along the circumferential direction. Moreover, when formed continuously along the circumferential direction, the protrusions 10 can be arranged in a spiral shape on the outer peripheral surface of the embedded component 1, or they can be formed in an annular shape and continuously in the circumferential direction. In Example 13, the maximum height of the aggregated protrusions 30 is formed to be greater than 0.08% of the outer diameter OD of the embedded component 1, and it can be confirmed that the embedded component 1 and the motor housing on its outer peripheral side have a practical bonding strength.

[0105] Figure 5 The figure shows the reduced aggregated protrusion 30 of Example 11, which is reduced so that the length in the horizontal axis direction of the average solid portion total graph becomes 1 / 2 of the length. Figure 5 The embedded component 1 shown in the average solid portion total graph has a steeply sloped portion of the average solid portion curve. When the embedded component 1 is formed with a portion having a steeply sloped average solid portion curve, the forces generated by the solidification and thermal contraction of the aluminum alloy in the circumferential direction are more easily generated in the circumferential direction. This prevents peeling even in a solid cutting test, resulting in excellent results. This has been confirmed to contribute to improved bonding strength between the embedded component 1 and the motor housing on its outer peripheral surface.

[0106] Figure 3 The figure shows the reduced aggregated protrusion 303 of Example 2 after the aggregated protrusion 30 is reduced so that the length in the horizontal axis direction of the average solid portion total graph becomes 1 / 2 of the length. Figure 3 In the embedded component 1 related to the average solid portion total diagram shown in FIG, the protrusion 30 after aggregation has, for example, Figure 2 As shown, a hook shape with a maximum peak point and a minimum peak point is formed midway between the distal end portion 11 and the proximal end portion 12. Furthermore, in this case, in the average solid portion total graph, it can be confirmed that the maximum peak point appears closer to the distal end than the minimum peak point.

[0107] As described above, in the embodiment 2, statistically speaking, the protrusion 10 formed on the outer peripheral surface of the insert member 1 has a hook shape. This hook shape of the protrusion 10 securely engages with the outer peripheral surface of the motor case, significantly improving the bonding strength between the insert member 1 and the outer peripheral surface of the motor case.

[0108] [Effects]

[0109] The protrusions 10 formed on the outer peripheral surface of the insert member 1 can improve the bonding strength between the insert member 1 and the motor housing on its outer peripheral surface side and prevent the insert member 1 from being displaced or offset in the axial, circumferential, and radial directions relative to the motor housing.

[0110] If multiple protrusions 10 are arranged on the outer circumferential surface of the insert member 1 with appropriate spacing between adjacent protrusions 10, the aluminum alloy flowing into the mold will appropriately spread between the multiple protrusions 10. This results in less gaps between the motor housing and the insert member 1, improving the joint strength between the motor housing and the insert member 1. In particular, even in motor housings manufactured using gravity casting, where aluminum alloy is considered difficult to spread throughout, the aluminum alloy easily spreads between the protrusions on the outer circumferential surface of the insert member 1.

[0111] Furthermore, the insert member 1 is securely fixed to the motor housing in the axial, circumferential, and radial directions. This prevents the stator from shifting in any direction, even when the inner circumference of the insert member 1 is machined and the stator is engaged with the inner circumferential surface 40 using the insert member 1 as a stator retainer and the motor is operated. As a result, the motor's reliability, durability, and continuous operating life can be improved, while friction-reduced losses and performance can be reduced.

[0112] The insert member 1 of the present invention ensures the joint strength between the motor housing and the insert member 1, thereby preventing the occurrence of misalignment and microscopic gaps between the insert member 1 and the motor housing. Furthermore, by preventing such misalignment and gaps, the surfaces of the gap are prevented from colliding with each other due to microvibrations during motor operation, thereby preventing a decrease in the durability of the motor itself.

[0113] While the embodiments of the present invention have been described above, each aspect disclosed in this specification may be combined with any other features disclosed in this specification.

Claims

1. An insert member for a rotating electrical machine, the insert member being a substantially cylindrical member to be cast into an aluminum alloy motor housing of the rotating electrical machine, wherein: A plurality of protrusions are formed on the outer peripheral surface of the embedded member. In one cutting surface, the embedded component is divided into a solid portion area and a non-solid portion area within a specified axial length, wherein the one cutting surface is one of the cutting surfaces that appear one by one on both sides of the central axis when the embedded component is cut in two along the axial direction using an imaginary plane containing the central axis of the embedded component, the solid portion area is an area on which the protrusion overlaps with a line segment parallel to the inner peripheral surface of the embedded component when the line segment overlaps with the one cutting surface, and the non-solid portion area is an area on which the protrusion does not overlap with a line segment parallel to the inner peripheral surface of the embedded component when the line segment overlaps with the one cutting surface. The value representing the ratio of the solid portion area on the line segment within the range of the predetermined axial length is defined as the solid portion ratio. The line segment is moved at predetermined intervals along the height direction of the protrusion from the top end toward the base end of the protrusion within the one cut surface of the embedded component to obtain each measurement point, and a graph is prepared as a total graph of the measured heights, in which the values of the solid portion ratios of the respective measurement points are sequentially plotted, with the solid portion ratios being represented on the horizontal axis and the distance from the top end in the height direction being represented on the vertical axis. The average of the solid portion ratios at the measurement points obtained through the plurality of cut surfaces is defined as an average solid portion ratio, and the solid portion total graph on which the average solid portion ratios are plotted is defined as an average solid portion total graph. In the average solid portion total graph, the position where the average solid portion ratio is 0 is set as the top end of the graph, and the position where the average solid portion ratio first exceeds 0.98, which is plotted sequentially from the top end side toward the base end side, is set as the base end of the graph, and When the distance from the top end portion to the base end portion in the figure is defined as the average maximum height of the protrusion, The average maximum height of the protrusion is not less than 0.08% of the outer diameter of the embedded member, In the average entity total graph, The total value of the average solid portion ratio in the range from the central position of the average maximum height of the protrusion to the base end portion in the figure, excluding the position of the base end portion in the figure, is greater than the total value of the average solid portion ratio in the range from the central position of the average maximum height of the protrusion to the top end portion in the figure, excluding the position of the top end portion in the figure.

2. The embedded component for a rotating electrical machine according to claim 1, wherein The average maximum height of the protrusions is formed within a range of 0.08% to 1% of the outer diameter of the insert member.

3. The embedded component for a rotating electrical machine according to claim 1, wherein The embedded component for a rotating electrical machine includes two or more measurement points plotted on the average solid portion total graph, The difference in the average solid portion ratio between the two or more measurement points is within a range of 0.10 or less, and the difference in the measurement height between the two or more measurement points is within a range of 0.05 mm or more.

4. The insert component for a rotating electrical machine according to any one of claims 1 to 3, wherein: The plurality of average solid portion ratios plotted on the average solid portion total graph have a maximum peak point where the value of the average solid portion ratio is maximum and a minimum peak point where the value of the average solid portion ratio is minimum. The position of the maximum peak point appears closer to the top end portion on the graph than the position of the minimum peak point.

5. The embedding member for a rotating electrical machine according to claim 4, wherein In the average entity total graph, The value of the average solid portion ratio at the minimum peak point is 0.08 or greater.

6. The embedding member for a rotating electrical machine according to claim 4, wherein In the average entity total graph, A difference between a value of the average substantial portion ratio at the maximum peak point and a value of the average substantial portion ratio at the minimum peak point is 0.02 or more and 0.20 or less.

7. The embedding member for a rotating electrical machine according to claim 4, wherein In the average entity total graph, The value of the average solid portion ratio at the maximum peak point is 0.50 or less.

8. The embedding member for a rotating electrical machine according to claim 1, wherein On the outer peripheral surface of the embedded member, The protrusion is formed only on a portion of the outer peripheral surface.

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