Winding excitation motor

Abstract

The invention relates to a winding excitation motor. The winding excitation motor is provided with: a shaft having a hollow portion; the rotor iron core is fixed on the shaft; and a rotor coil wound around the rotor core, the rotor core comprising: a cylindrical back yoke; a plurality of teeth which radially extend from the outer peripheral surface of the back yoke toward the outside in the radial direction, and on which a rotor coil is wound; and a cooling hole provided in each of the plurality of teeth and extending in the axial direction.

Description

Technical Field

[0001] The present disclosure relates to winding-field electric machines. Background Art

[0002] Japanese Patent Application Laid-Open No. 2020-39230 describes a technique for providing cooling holes near the shaft of a rotor core in a coil-excited motor. This technique forms a refrigerant path in the back yoke of the rotor core, through which refrigerant, used for oil cooling of the shaft, is passed to achieve cooling.

[0003] However, Japanese Patent Application Laid-Open No. 2020-39230 has room for improvement from the viewpoint of cooling performance inside the wound coil. Summary of the Invention

[0004] The present disclosure has been made in view of the above circumstances, and an object thereof is to provide a winding-excited motor capable of improving cooling performance.

[0005] In order to solve the above problems and achieve the purpose, the winding excitation motor disclosed in the present invention has:

[0006] a shaft having a hollow portion;

[0007] a rotor core fixed to the shaft; and

[0008] a rotor coil wound on the rotor core,

[0009] The rotor core comprises:

[0010] Cylindrical back yoke;

[0011] a plurality of teeth, the plurality of teeth radially extending from an outer peripheral surface of the back yoke toward the radially outer side and having the rotor coil wound therearound; and

[0012] A cooling hole is provided on each of the plurality of teeth and extends along the axial direction.

[0013] According to the present disclosure, there is an effect of being able to improve cooling performance. DETAILED DESCRIPTION

[0014] Features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will be described below with reference to the accompanying drawings, in which like reference numerals represent like elements, and in which:

[0015] Figure 1 is an overall top view of a winding-excited motor including one embodiment;

[0016] Figure 2 yes Figure 1 AA line cross-sectional view;

[0017] Figure 3 This is a schematic structural diagram of a rotor included in a winding-field motor according to one embodiment;

[0018] Figure 4 It will Figure 3 A local enlarged view of the area D1 after enlargement;

[0019] Figure 5 is an overall plan view illustrating the flow path of the refrigerant in the coil-excited motor 1;

[0020] Figure 6 yes Figure 5 BB line cross-sectional view.

[0021] The following describes a winding-field motor according to an embodiment of the present disclosure with reference to the accompanying drawings. It should be noted that the components in the following embodiments include components that can be easily replaced by those skilled in the art or are substantially the same components. Furthermore, the figures referenced in the following description merely schematically illustrate shapes, sizes, and positional relationships to facilitate understanding of the present disclosure. That is, the present disclosure is not limited solely to the shapes, sizes, and positional relationships illustrated in the figures.

[0022] Structure of winding excitation motor

[0023] Figure 1 It is an overall top view of a winding-field motor including one embodiment. Figure 2 yes Figure 1 AA line section view. Figure 3 This is a schematic structural diagram of a rotor included in a winding-field motor according to one embodiment. Figure 4 It will Figure 3 A partial enlarged view of the area D1. Figures 1 to 4 In the description, the axial direction is referred to as the X direction, the circumferential direction perpendicular to the axial direction is referred to as the Y direction, and the depth direction perpendicular to the axial direction is referred to as the Z direction.

[0024] Figures 1 to 4 The winding field motor 1 shown includes a substantially cylindrical stator 10 fixed to a frame (not shown) and a rotor 20 rotatably held on the inner circumference of the stator 10. The winding field motor 1 also includes a stator cooling pipe 30 for cooling the stator 10 and an ATF temperature sensor 40 (see FIG. 1 ) for detecting the temperature of the cooling oil. Figure 2 ), and a stator coil temperature sensor 50 for detecting the temperature of the stator 10 (see Figure 2 ).

[0025] The stator 10 includes a stator core 11 and a stator coil 12 wound around the stator core 11. The stator coil 12 is wound around a plurality of teeth (not shown) provided radially inward of the stator core 11.

[0026] The rotor 20 includes a shaft 21 , a rotor core 22 fixed to the shaft 21 , a rotor coil 23 wound around the rotor core 22 , and a hard portion 24 .

[0027] The shaft 21 has a hollow portion 21 a and shaft-side cooling holes 21 b and 21 c extending from the hollow portion 21 a toward the outer peripheral surface of the shaft 21 at the upper and lower ends of the hollow portion 21 a in the axial direction, respectively.

[0028] The rotor core 22 includes a cylindrical back yoke 22a, a plurality of teeth 22b extending radially outward from the outer peripheral surface of the back yoke 22a, and a plurality of teeth 22b extending radially outward from the outer peripheral surface of the back yoke 22a. Figure 1 8 in total), and slots (not shown) formed by the back yoke 22a and the teeth 22b.

[0029] The rotor core 22 also includes a plurality of cooling holes 22c, each provided in the plurality of teeth 22b and extending axially. Refrigerant, such as cooling oil, flows from one of the shaft-side cooling holes 21b and the shaft-side cooling holes 21c through the gaps between the plurality of cooling holes 22c. The gaps are the gaps between the rotor coils 23 (not shown) and the rotor core 22, described later, and are gaps through which insulating paper (not shown) is interposed. The plurality of cooling holes 22c each have injection ports 22d, alternately provided circumferentially on the upper or lower ends of the plurality of teeth 22b, for injecting (discharging) refrigerant. Hereinafter, the side from which refrigerant is ejected from the upper end of the tooth 22b is referred to as refrigerant injection port 22d1, and the side from which refrigerant is ejected from the lower end of the tooth 22b is referred to as refrigerant injection port 22d2.

[0030] The rotor coil 23 is formed by winding a coil wire around the teeth 22 b and is housed in the slots.

[0031] The hard portion 24 is filled between the rotor coil 23 and the slot 23 c and is hardened in a state where the coil end of the rotor coil 23 is exposed.

[0032] Refrigerant flow

[0033] The flow of the refrigerant with respect to the coil-excited motor 1 configured as described above will be described. Figure 5 It is an overall plan view illustrating the flow path of the refrigerant in the coil-excited motor 1 . Figure 6 yes Figure 5 BB line cross-sectional view. Figure 5 as well as Figure 6 , arrows schematically indicate the flow of refrigerant.

[0034] like Figure 5 as well as Figure 6 As shown, the coil-excited motor 1 is connected to a heat exchanger 100 and a pump 200 via a flow path such as a pipe (not shown), and is cooled by a refrigerant supplied from the pump 200 .

[0035] The pump 200 supplies coolant to the stator cooling pipe 30 and the hollow portion 21 a of the shaft 21 via a flow path (not shown). In this case, the coolant ejected (discharged) from the stator cooling pipe 30 cools the surfaces of the stator 10 and the rotor 20 and circulates through the pump 200 .

[0036] The refrigerant supplied to the hollow portion 21a of the shaft 21 then flows through the plurality of cooling holes 22c provided in the teeth 22b of the rotor core 22. The refrigerant in each of the plurality of cooling holes 22c is then ejected (discharged) from the refrigerant injection port 22d1 or the refrigerant injection port 22d2 provided in the teeth 22b of the rotor core 22, and circulates to the pump 200.

[0037] According to the embodiment described above, the coil-field motor 1 can directly cool the teeth 22b using the refrigerant. As a result, compared to conventional cooling using slots 23c, this method provides tooth cooling with a larger surface area in contact with the rotor coil 23, allowing cooling of the inside of the rotor coil 23 wound around the teeth.

[0038] Furthermore, according to one embodiment, the coil-field motor 1 has refrigerant injection ports 22d1 and 22d2 provided on the upper end side of the teeth 22b of the rotor core 22. This configuration prevents the refrigerant from becoming hotter when it reaches the opposite side of the rotor core 22 (from the lower end to the upper end), as occurs with conventional methods where the refrigerant is injected (discharged) from only one side. As a result, this method allows for more efficient cooling than conventional methods where the refrigerant is injected (discharged) from only one side, thus enabling uniform cooling of the rotor 20.

[0039] Those skilled in the art will readily derive further effects and variations. The broader aspects of the present invention are not limited to the specific detailed and representative embodiments shown and described above. Therefore, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.

[0040] While several embodiments of the present application have been described in detail above with reference to the drawings, these are merely examples, and the embodiments described in the disclosure section of the present invention are representative. The present invention can be implemented in other embodiments with various modifications and improvements based on the knowledge of those skilled in the art.

Claims

1. A winding excitation motor, wherein: The winding excitation motor has: a shaft having a hollow portion; a rotor core fixed to the shaft; and a rotor coil wound on the rotor core, The rotor core comprises: Cylindrical back yoke; a plurality of teeth, the plurality of teeth radially extending from an outer peripheral surface of the back yoke toward the radially outer side and having the rotor coil wound therearound; and A cooling hole is provided on each of the plurality of teeth and extends along the axial direction.

2. The winding-excited motor according to claim 1, wherein: The cooling hole has injection ports that are alternately provided along the circumferential direction on the upper end side or the lower end side of each of the plurality of teeth and inject refrigerant.

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