motor

Abstract

To provide a motor having a stator with improved cooling efficiency. [Solution] The motor 1 of the present invention is a motor 1 having a stator 30, the stator 30 comprising a stator core 31 and a hollow coil (stator coil 32) provided on the stator core 31 and having a hollow refrigerant flow path inside. For example, the hollow coil comprises a plurality of coil members 32CC having a one-side opening OP opening at one end and a other-side opening opening at the other end, and having a hollow refrigerant flow path inside, a one-side coil end 321A provided on one side of the stator 30 and joined so as to maintain the one-side opening OP by crossing the one-side ends, and a other-side coil end 321B provided on the other side of the stator 30 and joined so as to maintain the other-side opening by crossing the other-side ends.

Description

Technical Field

[0001] The present disclosure relates to a motor having a stator.

Background Art

[0002] In Patent Document 1, conventionally, the outer periphery of the stator core is in contact with the inner periphery of the frame and is cooled by the refrigerant liquid flowing through the flow path of the frame. However, it is explained that if the flow path is arranged radially outward, the flow path will be separated from the stator core, resulting in a problem of deteriorated cooling efficiency.

[0003] In order to solve this problem, Patent Document 1 discloses a stator structure including a stator having a stator core and a stator coil wound around the stator core, a bus bar to which the stator coil is connected, a bus ring having an outer diameter larger than the outer diameter of the stator core, a frame that houses the stator core radially inward and has a flow path for refrigerant liquid that opens at one end in the axial direction and extends in the other axial direction, and a lid member that is arranged on one axial side of the frame and on the other axial side of the bus ring, closes the opening of the flow path, and holds the bus ring. The lid member is fixed to the frame.

[0004] And Patent Document 1 describes that with this stator structure, the opening of the flow path in the frame can be closed by the lid member instead of being closed by a bracket. As a result, the radial position of the flow path can be determined regardless of the shape of the bus ring, and thus the flow path can be arranged on the inner diameter side of the frame, that is, on the side closer to the stator core, improving the cooling efficiency.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, the stator structure disclosed in Patent Document 1 still cools the stator from the outside, and it is desirable to be able to cool the stator more efficiently.

[0007] This invention has been made in view of these circumstances, and one of its objectives is to provide a motor having a stator with improved cooling efficiency. [Means for solving the problem]

[0008] To achieve the above objective, the present invention is understood by the following configuration. The motor of the present invention is a motor having a stator, The stator is, Stator core and The stator core is provided with a hollow coil having a hollow refrigerant flow path inside. [Effects of the Invention]

[0009] According to the present invention, a motor having a stator with improved cooling efficiency is provided. [Brief explanation of the drawing]

[0010] [Figure 1] This is a cross-sectional view of a motor having a stator according to an embodiment of the present invention. [Figure 2] This is a cross-sectional view along line AA in Figure 1. [Figure 3] This is a partial perspective view of a stator showing one coil end of an embodiment according to the present invention. [Figure 4] This is a side view of a pair of coil members according to an embodiment of the present invention, with their one ends intersecting, as seen from a direction perpendicular to the rotation axis. [Figure 5] This is a front view from one side in the direction of the rotation axis, showing a state in which one end of a pair of coil members according to an embodiment of the present invention is crossed. [Modes for carrying out the invention]

[0011] Hereinafter, embodiments for carrying out the present invention (hereinafter referred to as "embodiments") will be described in detail with reference to the attached drawings. Throughout the description of the embodiments, the same elements are assigned the same numbers or reference numerals. Furthermore, the dimensional ratios in the drawings differ from the actual dimensional ratios and are merely for illustrative purposes to make the explanation easier to understand; there is no guarantee that identical parts are depicted with the same dimensions across different drawings. Furthermore, schematic diagrams are included to make the structure easier to understand. In these diagrams, for the sake of readability, only some of the parts with the same attribute that exist in multiple locations may be assigned reference numerals.

[0012] A motor 1 having a stator 30 according to an embodiment of the present invention will be described with reference to Figures 1 to 5.

[0013] Figure 1 is a cross-sectional view of a motor 1 having a stator 30 according to an embodiment of the present invention, and is a cross-sectional view along the rotor shaft 21. In the following, when viewed in a plane perpendicular to the rotation axis of the rotor 20 (described later), the direction farther from the rotation axis of the rotor 20 is defined as the radially outward direction, and conversely, the direction closer to the rotation axis is defined as the radially inward direction.

[0014] Furthermore, when viewed in a plane perpendicular to the rotation axis of the rotor 20, the direction along the rotation axis of the rotor 20 is defined as the circumferential direction.

[0015] Furthermore, the direction of the rotor 20's axis of rotation (the longitudinal direction of the rotor shaft 21 passing through the center of rotation of the rotor shaft 21, described later) is defined as the axis of rotation. In other words, the direction of the axis of rotation is also the direction of the straight line perpendicular to the plane perpendicular to the axis of rotation.

[0016] As shown in Figure 1, the motor 1 comprises a case 10, a rotor 20 rotatably housed within the case 10, and a stator 30 housed within the case 10 so as to cover the radially outer side of the rotor 20.

[0017] In addition, the motor 1 includes a bearing portion BR that is fixed to the case 10 and rotatably supports the rotor 20, and a rotation angle detection portion VR that detects the rotation angle of the rotor 20.

[0018] Specifically, the bearing portion BR includes a one-side bearing BR1 that is fixed to a portion of the case 10 located on one side in the rotation axis direction of the rotor 20, and a the other-side bearing BR2 that is fixed to a portion of the case 10 located on the other side in the rotation axis direction of the rotor 20.

[0019] For example, as an example, the one-side bearing BR1 and the other-side bearing BR2 may be radial ball bearings or the like.

[0020] In this case, as shown in FIG. 1, the one-side bearing BR1 and the other-side bearing BR2 include an annular inner ring IR having a through hole at the center for fixing a rotor shaft 21 (described later) of the rotor 20, an annular outer ring OR having a through hole at the center for receiving the inner ring IR, and balls BL that are arranged in an annular space between the inner ring IR and the outer ring OR for the rotation of the inner ring IR and the outer ring OR and are provided in a plurality in the circumferential direction of the annular space.

[0021] And the one-side bearing BR1 is such that the outer ring OR is fixed (for example, press-fitted) to a one-side bearing fixing portion 10A provided in a portion of the case 10 located on one side in the rotation axis direction of the rotor 20, and one side of the rotor shaft 21 (described later) is fixed (for example, press-fitted) to the through hole at the center of the inner ring IR. Note that it may be fixed by other fixing methods such as performing adhesive fixing instead of press-fitting.

[0022] Similarly, the other-side bearing BR2 is such that the outer ring OR is fixed (for example, press-fitted) to a the other-side bearing fixing portion 10B provided in a portion of the case 10 located on the other side in the rotation axis direction of the rotor 20, and the other side of the rotor shaft 21 (described later) is fixed (for example, press-fitted) to the through hole at the center of the inner ring IR. Alternatively, the parts may be fixed using adhesive bonding instead of press-fitting.

[0023] In this way, one side and the other side of the rotor shaft 21 (described later) of the rotor 20 are rotatably fixed to the case 10 via bearing BR1 on one side and bearing BR2 on the other side, so that the rotor 20 can rotate relative to the case 10.

[0024] Furthermore, for example, the rotation angle detection unit VR can be a resolver or the like. In this case, as shown in Figure 1, the rotation angle detection unit VR comprises a rotor VR1 fixed to the rotor shaft 21 (described later) of the rotor 20 and rotating together with the rotor shaft 21 (described later), and a stator VR2 that rotatably receives the rotor VR1.

[0025] In this embodiment, the rotor VR1 is fixed to one side of the rotor shaft 21 (described later) of the rotor 20, and the stator VR2 is positioned within the case 10 at a location corresponding to the stator VR1. For example, the rotor VR1 may be rotatably integrated with the stator VR1.

[0026] (Case 10) The case 10 comprises a case body 11 having an opening that opens to the other side in the direction of the rotor 20's rotation axis and a housing space for housing the rotor 20 and the stator 30, and a lid 12 provided to close the opening of the case body 11. As shown in Figure 1, the one-side bearing fixing portion 10A, which fixes the outer ring OR of one-side bearing BR1, is provided on the case body 11, and the other-side bearing fixing portion 10B, which fixes the outer ring OR of the other-side bearing BR2, is provided on the lid portion 12.

[0027] (Rotor 20) As shown in Figure 1, the rotor 20 comprises a rotor shaft 21 and a rotor core 22 provided on the rotor shaft 21.

[0028] For example, the rotor 20 may be a wound-field type rotor, in which case the rotor 20 includes rotor coils (not shown) provided on the rotor core 22.

[0029] Specifically, the rotor core 22 has teeth portions 31A that protrude radially outward, and coil wires for field coils that form the rotor coils are wound around the teeth portions 31A.

[0030] Furthermore, the rotor 20 is not limited to a wound-field type; instead of rotor coils, the rotor core 22 may be magnetized such that S poles and N poles alternately appear in the circumferential direction of the rotor core 22. Alternatively, instead of magnetization, permanent magnets may be provided on the rotor core 22.

[0031] Thus, the rotor 20 can use a rotor that is commonly used in inner-rotor type motors.

[0032] (Stator 30) Figure 2 is a cross-sectional view of line AA in Figure 1, and mainly shows the stator core 31 and stator coil 32.

[0033] In Figure 2, the left side shows the entire cross-section, while the right side is a magnified view of the area enclosed by the dotted rectangle.

[0034] As shown in Figure 2, the stator 30 comprises a stator core 31 having a plurality of teeth 31A that protrude radially inward and are spaced evenly apart in the circumferential direction, and a stator coil 32 provided on the stator core 31.

[0035] Furthermore, the stator coil 32 in this embodiment is a coil comprising a conductor portion 32A having a hollow refrigerant flow path inside, and an insulating coating portion 32B covering the outer circumference of the conductor portion 32A, that is, a hollow coil having a hollow refrigerant flow path inside.

[0036] In this embodiment, since the motor 1 is a three-phase motor, the stator 30 is equipped with a stator coil 32 for the U-phase (a hollow coil for the U-phase), a stator coil 32 for the V-phase (a hollow coil for the V-phase), and a stator coil 32 for the W-phase (a hollow coil for the W-phase), which are wound around the stator core 31 and correspond to the three phases of U-phase, V-phase, and W-phase.

[0037] The stator coils 32, corresponding to the U-phase, V-phase, and W-phase, which are wound around the stator core 31, are connected to an inverter circuit that controls the supply of current via electrical connection parts EC (U-phase connection part EC1, V-phase connection part EC2, and W-phase connection part EC3). Note that the U-phase connection EC1, V-phase connection EC2, and W-phase connection EC3 are sometimes referred to as busbars.

[0038] Specifically, the stator coil 32 for the U phase (a hollow coil for the U phase) is connected to the inverter circuit via the U phase connection part EC1, the stator coil 32 for the V phase (a hollow coil for the V phase) is connected to the inverter circuit via the V phase connection part EC2, and the stator coil 32 for the W phase (a hollow coil for the W phase) is connected to the inverter circuit via the W phase connection part EC3.

[0039] In this embodiment, as shown in Figure 1, the stator coil 32 (hollow coil) comprises a one-side coil end 321A provided on one side of the stator 30 when viewed in the direction of the rotation axis of the rotor 20, and a other-side coil end 321B provided on the other side of the stator 30. These coil ends (one-side coil end 321A and the other-side coil end 321B) will be described in more detail, mainly with reference to Figures 3 to 5.

[0040] Figure 3 is a partial perspective view of the stator 30 showing one coil end 321A of an embodiment according to the present invention, and is a schematic diagram drawn for clarity.

[0041] Figure 4 is a schematic diagram drawn for clarity, showing a state in which one end of a pair of coil members 32CC of an embodiment according to the present invention is crossed, viewed from a direction perpendicular to the rotation axis.

[0042] Figure 5 is a schematic front view, drawn for clarity, showing a state in which one end of a pair of coil members 32CC according to an embodiment of the present invention is crossed, as seen from one side in the direction of the rotation axis.

[0043] In the following, we will describe one coil end 321A of the stator coil 32 (hollow coil) with reference to Figures 3 to 5. However, since the other coil end 321B is basically the same as the one coil end 321A, we may omit explanations of similar points.

[0044] As shown in Figures 3 to 5, the stator coil 32 (hollow coil) comprises a plurality of coil members 32CC having a one-side opening OP (see Figures 3 and 5) that opens at one end and a other-side opening (not shown) that opens at the other end when viewed in the direction of the rotation axis of the rotor 20, and having a hollow refrigerant flow path inside.

[0045] Then, one coil end 321A is formed by joining the one ends of a pair of coil members 32CC so as to cross each other and maintain one opening OP, and similarly, the other coil end 321B is formed by joining the other ends of a pair of coil members 32CC so as to cross each other and maintain another opening (not shown).

[0046] Specifically, as shown in Figures 3 and 5, the ends of a pair of coil members 32CC are crossed, and a welded section WLD is formed at the contact point by laser welding or the like to prevent the opening OP on one side from being blocked, thereby joining the ends of a pair of coil members 32CC.

[0047] On the other hand, the other coil end 321B is formed by joining one coil member 32CC (member A or member B) of a pair of coil members 32CC (for example, member A and member B) formed by joining the one ends of the coil members 32CC described above, and a coil member 32CC (for example, member C) that is adjacent to the pair of coil members 32CC that join the one ends of the coil members 32CC, and by crossing the other ends of the pair of coil members 32CC (for example, the other ends of member A and member C, or the other ends of member B and member C) and forming a welded section WLD at the contact point by laser welding or the like so that the other side opening (not shown) is not closed, thereby joining the other ends (for example, the other ends of member A and member C, or the other ends of member B and member C).

[0048] In this way, by shifting the pair of coil members 32CC that are joined at one coil end 321A and the other coil end 321B, the stator coil 32 (hollow coil) becomes wound around the stator core 31.

[0049] Furthermore, since the insulating coating portion 32B at one end and the other end of the coil member 32CC is removed during the joining process described above, an insulating treatment is applied to the surface after the joining process described above, although it is not shown in Figures 3 to 5.

[0050] As described above, the stator coil 32 is a hollow coil having a hollow refrigerant flow path inside, with one opening OP of the hollow portion (refrigerant flow path) opening to one coil end 321A, and the other opening (not shown) of the hollow portion (refrigerant flow path) opening to the other coil end 321B (see Figure 1). For example, if refrigerant is supplied to one opening OP, the supplied refrigerant will flow toward the other opening (not shown). For example, an oil such as ATF can be used as the refrigerant.

[0051] Therefore, as shown in Figure 1, the motor 1 includes an annular one-side cover CV1 that covers one-side coil end 321A so that refrigerant can flow through one-side opening OP (see Figure 3), and an annular other-side cover CV2 that covers the other-side coil end 321B so that refrigerant can flow through the other-side opening (not shown).

[0052] As shown in Figure 1, the one-sided cover CV1 has an opening that opens toward the other side when viewed in the direction of the rotation axis of the rotor 20, and is equipped with an annular one-sided housing space (also called an annular one-sided housing recess) that accommodates the one-sided coil end 321A.

[0053] Furthermore, as shown in Figure 1, the other side cover CV2 has an opening that opens toward one side when viewed in the direction of the rotation axis of the rotor 20, and is equipped with an annular other side housing space (also called an annular other side housing recess) that accommodates the other side coil end 321B.

[0054] Furthermore, as shown in Figure 1, the motor 1 includes a ring-shaped outer sealing member OSC1 provided between the edge of an opening located radially outward of one side cover CV1 and the case body 11, a ring-shaped inner sealing member ISC1 provided between the edge of an opening located radially inward of one side cover CV1 and the stator core 31, a ring-shaped outer sealing member OSC2 provided between the edge of an opening located radially outward of the other side cover CV2 and the case body 11, and a ring-shaped inner sealing member ISC2 provided between the edge of an opening located radially inward of the other side cover CV2 and the stator core 31.

[0055] Furthermore, the base portions of the coil end 321A on one side and the coil end 321B on the stator core 31 side are also provided with a sealant (e.g., a sealing resin, etc.) not shown, to prevent refrigerant from leaking into the gap between the teeth 31A of the stator core 31.

[0056] However, there are usage scenarios where it is acceptable for the refrigerant to flow to the rotor 20 side, and in these cases, a small amount of refrigerant leaking into the gap between the teeth 31A is not a problem, so this sealant may not be necessary.

[0057] Then, when refrigerant is supplied to the one-side housing space that houses the one-side coil end 321A, the supplied refrigerant flows through the hollow coil (stator coil 32) toward the other-side housing space that houses the other-side coil end 321B, cooling the stator 30.

[0058] Furthermore, the refrigerant (e.g., oil) in the other side housing space that accommodates the other coil end 321B is supplied back into the one side housing space that accommodates the one coil end 321A via a cooling device (e.g., an oil cooler) after being cooled by the cooling device.

[0059] In this embodiment, as described above, a case has been described in which a refrigerant (e.g., oil) is supplied into the hollow coil (stator coil 32) from one side opening OP (see Figures 3 and 5) and discharged from the other side opening (not shown). However, the embodiment is not limited to this, and a refrigerant (e.g., oil) may be supplied into the hollow coil (stator coil 32) from the other side opening (not shown) and discharged from the one side opening OP (see Figures 3 and 5).

[0060] In other words, a coolant may be supplied to the other side housing space that houses the other side coil end 321B, and the supplied coolant may flow through the hollow coil (stator coil 32) toward the one side housing space that houses the one side coil end 321A, thereby cooling the stator 30.

[0061] In this case, it is sufficient that the refrigerant (e.g., oil) in the one-side housing space housing the one-side coil end 321A is supplied to the other-side housing space housing the other-side coil end 321B, after being cooled by a cooling device (e.g., an oil cooler).

[0062] Therefore, in this embodiment described with reference to the drawings, the left side of Figure 1 is designated as one coil end 321A and the right side as the other coil end 321B. However, this distinction is not particularly necessary; one of the coil ends at both ends of the stator core 31 can be designated as one coil end and the other coil end as the other coil end.

[0063] According to the motor 1 of the above embodiment, instead of indirectly cooling the stator 30 from the outside, a coolant (for example, oil) is supplied to the stator 30 to cool it directly, thereby improving cooling efficiency.

[0064] Specifically, in the above embodiment, the motor 1 flows a coolant (for example, oil) through the hollow coil which is the stator coil 32, directly cooling the stator 30, thus improving cooling efficiency.

[0065] Thus, the motor 1 of this embodiment can efficiently cool the stator 30, making it suitable for applications where high cooling efficiency is required.

[0066] For example, though not limited to this embodiment, the motor 1 of this embodiment can be suitably used in a rotating electric machine used for driving an automobile.

[0067] Although the present invention has been described above based on specific embodiments, the present invention is not limited to the above embodiments. In the above embodiment, the stator coil 32 was formed by joining together a plurality of hollow coil members 32CC and winding them around the stator core 31, but the stator coil is not limited to being formed in this manner.

[0068] For example, the stator coil may be made by winding a coil member, such as a long, hollow coil wire, around the stator core using a winding machine or the like.

[0069] In this case, since openings in the hollow coil appear at the winding start and end ends of the stator coil, refrigerant can be supplied to either the winding start end or the winding end opening of the hollow coil, so that the supplied refrigerant flows through the hollow coil toward the winding end or the other opening of the hollow coil at the winding start end.

[0070] In the above embodiment, the refrigerant is supplied to many openings (for example, one-side opening OP (see Figures 3 and 5)), flows through a hollow coil, and is discharged from many openings (for example, the other-side opening (not shown)), so the distance the refrigerant travels is short. Therefore, compared to when the refrigerant flows over a long distance through a hollow coil, the rise in temperature of the refrigerant can be suppressed.

[0071] Therefore, this method provides a higher cooling effect than winding a long, hollow coil wire around the stator core using a winding machine or similar device.

[0072] This does not rule out the case where a long, hollow coil wire is wound around the stator core using a winding machine or the like, but from the standpoint of cooling efficiency, it is preferable that the stator coil 32 (hollow coil) has a number of openings OP on one side (see Figures 3 and 5) and a number of openings on the other side (not shown), as in the above embodiment.

[0073] As described above, the present invention includes modifications and improvements to the embodiments, and this is evident to those skilled in the art from the claims. [Explanation of Symbols]

[0074] 1...Motor, 30...Stator, 31...Stator core, 32...Stator coil (hollow coil), 32CC...Coil component, 321A...One coil end, 321B...Other coil end, CV1...One cover, CV2...Other cover, OP...One opening

Claims

1. A motor having a stator, The stator is, Stator core and A motor comprising a hollow coil provided on the stator core and having a hollow refrigerant flow path inside.

2. The aforementioned hollow coil is Multiple coil members having one side opening that opens at one end and another side opening that opens at the other end, and having a hollow refrigerant flow path inside, A one-side coil end is provided on one side of the stator, and the two one-side ends are joined together so as to intersect and maintain the one-side opening, The motor according to claim 1, further comprising: a coil end provided on the other side of the stator, which is joined so as to intersect the ends of the other side and maintain the opening on the other side.

3. The aforementioned motor is A one-side cover that covers the one-side coil end so that the refrigerant can flow through the one-side opening, The motor according to claim 2, further comprising: a other-side cover that covers the other-side coil end so that a refrigerant can flow through the other-side opening.

4. The motor according to claim 2 or claim 3, wherein the refrigerant is supplied into the hollow coil from the one-sided opening and discharged from the other-sided opening.

Images